GB2562378A - Self-propelled windrower with towing mode for use with a pull-type mower conditioner - Google Patents

Abstract

A method implemented in a machine comprises a first steering mode in which a left drive wheel and a right drive wheel 14 concurrently rotate, wherein the rotation of the left drive wheel is in a direction opposite that of the rotation of the right drive wheel and a second steering mode in which the left and right drive wheels rotate concurrently in the same direction and enabling one or more caster wheels 14A to freely steer rotate in the first steering mode and to steer-rotate according to a limited arc in the second steering mode. Also disclosed is a windrower having a plural drive wheels, a sensor, steering cylinder, a user interface and a controller, the windrower having a dual-path steering mode and a tailwheel steering mod wherein, in the dual-path steering mode the position of tailwheel casters are not controlled and in a tailwheel steering mode the steer-rotation of the caster wheels is limited based on caster steer position information received from the sensor.

Description

SELF-PROPELLED WINDROWER WITH TOWING MODE FOR USE WITH A PULL-

TYPE MOWER CONDITIONER

BACKGROUND OF THE INVENTION

Field of Invention

The present disclosure is generally related to agricultural machines and, more particularly, self-propelled windrowers.

Description of Related Art

Agricultural pull-type implements are generally towed by a tractor using a hitch assembly coupled to a drawbar of the tractor. Self-propelled windrowers utilize a dualpath steering system to achieve maximum maneuverability while cutting crops in the field. However, this steering system is not ideal for high speed transport due to the machine’s inherent instability. In addition, the machine is not suited for pulling a towed implement, such as a header with a transport kit installed, due to a zero radius turning that the machine is capable of via the dual-path steering functionality.

Such a maneuver, even if unintentional, may result in the windrower and towed implement becoming “jack-knifed.”

OVERVIEW OF THE INVENTION

In one embodiment, the invention is directed a windrower machine operable in two steering modes selectable by an operator of the machine, the dual steering modes being a dual-path steering mode and a tailwheel steering mode, the two steering modes being mutually exclusive. The machine includes a chassis and an engine mounted on the chassis. The machine also includes plural drive wheels coupled to the chassis and a ground drive system having plural wheel motors and plural hydraulic wheel propel pumps coupled to a respective one of the plural drive wheels, the hydraulic wheel propel pumps being powered by the engine and each wheel motor being powered by its respective hydraulic wheel propel pump. The machine also has plural tailwheel caster assemblies coupled to opposing sides of the chassis, each tailwheel caster assembly having a tailwheel caster, a sensor, and a steering cylinder configured to operably control a steering position of the tailwheel caster when in the tailwheel steering mode.

In another embodiment, the invention is directed to a method implemented in a machine including in a first steering mode, causing a left drive wheel and a right drive wheel to concurrently rotate, wherein the rotation of the left drive wheel is in a direction opposite that of the rotation of the right drive wheel; and in a second steering mode nonoverlapping in operation with the first steering mode, causing the left drive wheel and the right drive wheel to rotate concurrently in only a same direction.

These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. FIG. 1 is a schematic diagram that illustrates, in top fragmentary plan view, an embodiment of an example windrower with an embodiment of a towing mode steering system.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Reference is made to FIG. 1, which illustrates an example agricultural machine where an embodiment of a steering axle system may be implemented. One having ordinary skill in the art should appreciate in the context of the present disclosure that the example agricultural machine, depicted in FIG. 1 as a self-propelled windrower 10, is merely illustrative, and that other machines and/or components with like functionality may deploy certain embodiments of a steering axle system. The self-propelled windrower 10 is operable to mow and collect standing crop in the field, condition the cut material as it moves through the machine to improve its drying characteristics, and then return the conditioned material to the field in a windrow or swath. In some implementations, the windrower 10 may tow an implement (not shown). The windrower 10 may include a chassis or frame 12 supported by a pair of front drive wheels 14 (although tracks may be used in some embodiments, or other configurations in the number and/or arrangement of wheels may be used in some embodiments) and a pair of rear caster wheels 16 for movement across a field to be harvested. In some embodiments, the amount of wheels 14 and/or 16 may be different. As is known, the chassis 12 further carries a cab (not shown), within which an operator may control certain operations of the windrower 10, and a rearwardly spaced compartment housing a power source, which in the depicted embodiment, comprises an internal combustion engine 18. The chassis 12 also supports a steering system that includes a dual-path steering system 20 (which is part of a ground drive system) and a steering axle system 22. Commonly assigned U.S. Patent Application No. 14/619,469 entitled Self-Propelled Agricultural Machine with Dual Driving Modes, and U.S. Patent Application No. 15/723,262 entitled Steering Axle for Self-Propelled Windrower, hereby incorporated by reference in their entirety, describe embodiment of suitable dual-path steering systems 20 and steering axle systems 22. A coupled working implement, depicted in FIG. 1 as a harvesting header 24, is supported on the front of the chassis 12 in a manner understood by those skilled in the art. The header 24 may be configured as a modular unit and consequently may be disconnected for removal from the chassis 12. As is also known in the art, the header 24 has a laterally extending crop cutting assembly in the form of a low profile, rotary style cutter bed located adjacent the front of the header 24 for severing crop from the ground as the windrower 10 moves across a field. However, one skilled in the art will understand that other types of crop cutting assemblies 24, such as sickle style cutter beds, may also be used in some embodiments. During a harvesting operation, the windrower 10 moves forward through the field with the header 24 lowered to a working height.

The windrower 10 comprises a ground drive system 26 that includes the dual-path steering system 20. The windrower 10 also includes a header drive system that comprises a header drive pump 28 that is fluidly coupled to header drive motors 30 and 32 via hydraulic fluid lines, including hydraulic fluid line 34, as is known. The ground drive system 26 is powered by the engine 18, which is mounted to the chassis 12. The ground drive system 26 comprises a pump drive gearbox 36 that is coupled to the engine 18. The ground drive system 26 further comprises the dual-path steering system 20, which includes a left wheel propel pump 38 coupled to the pump drive gearbox 36, and further coupled to a left wheel drive motor 40 via hydraulic fluid lines, including hydraulic fluid line 42. The dual-path steering system 20 of the ground drive system 26 also comprises a right wheel propel pump 44 coupled to the pump drive gearbox 36, and further coupled to a right wheel drive motor 46 via hydraulic fluid lines, including hydraulic fluid line 48. Although depicted as comprising a by-wire system, other hydraulic mechanisms may be used to facilitate ground transportation in some embodiments, and hence are contemplated to be within the scope of the disclosure.

The dual-path steering system 20 further comprises a controller 50A. For dual-path steering operations, in one embodiment, software in the controller 50A provides for control of the ground drive system 26, including the dual-path steering system 20. Sensors are located on or proximal to the machine navigation controls, or generally, a user interface (e.g., which includes the steering wheel and the forward-neutral-reverse (FNR) lever) in the cab of the windrower 10, where operator manipulation of the steering wheel and/or FNR lever causes movement of the same that is sensed by the sensors. These sensors feed signals to the controller 50A, which in turn provide control signals to the propel pumps 38 and 44 to cause movement of the windrower 10 according to the requested speed and travel direction. The signaling from the controller 50A causes a change in fluid displacement in the respective propel pumps 38 and 44, each displacement in turn driving the respective wheel drive motors 40 and 46 via hydraulic fluid lines 42 and 48. In general, dual-path steering is generally achieved through adjustment of differential speeds of the two drive wheels 14 in coordination with active steering by the steering axle system 22, the latter described further below. In some embodiments, the dual-path steering system 20 may comprise additional or fewer components.

As to the drive wheels 14, rotating the steering wheel may increase the speed of one drive wheel 14 (e.g., left) while slowing the speed of the other drive wheel 14 (e.g., right) by the same amount. In other words, steering for the windrower 10 may be achieved by increasing the speed of one drive wheel 14 while decreasing the speed of the opposite drive wheel 14 by the same amount (both drive wheels 14 may rotate at the same speed in the same direction or when in counter-rotation). Using some example values for illustration, if the windrower 10 is traveling at 5 miles per hour (MPH) forward, a steering command may result in the left drive wheel 14 driven at a speed of 6 MPH and the opposing right drive wheel 14 driven at a speed of 4 MPH, resulting in a right hand turn. As another example, if the windrower 10 is traveling forward at 1 MPH, the same steering command may result in the left drive wheel 14 being driven at 2 MPH forward and the opposing right drive wheel 14 driven to a complete stop (or equivalently, permitted to stop), with the magnitude of the difference in each case (e.g., 2 MPH) between the two drive wheels 14 being the same. At slower ground speeds, the drive wheels 14 may counter-rotate, where one drive wheel 14 is driven in the forward direction and the opposing drive wheel 14 is driven in reverse, causing the windrower 10 to spin in a zero radius turn. The zero radius turn is enabled during the neutral position of the FNR lever, and as described above, involves the drive wheels 14 rotating in opposite directions (e.g., while the left front drive wheel 14 is rotating in a clockwise direction, for instance, the right front drive wheel 14 is rotating in a counter-clockwise direction). Stated otherwise, for the zero radius turn function, the front drive wheels are driven (e.g., via the propel pumps 38 and 44 and wheel drive motors 40 and 46, as commanded or signaled by the controller 50A) in opposite directions (respectively forward and reverse). Continuing the illustrative examples described above, for a similar steering command and operation in neutral, the command results in the left drive wheel 14 driven at a speed of 1 MPH forward and the right drive wheel 14 driven 1 MPH in reverse (causing the windrower 10 to counter rotate to the right). The zero radius turn is a typical field operation used to achieve maximum maneuverability. Because of the manner of operation in dual-path steering, it is noted that the windrower 10 steers backwards when traveling in reverse (e.g., rotating the steering wheel to the left while backing up causes the windrower 10 to turn to the right, referred to as “S-steering”). At the same time, as noted above, the rear caster wheels 16 are also under active steering control using steering commands that are coordinated with those provided for controlling operations of the front drive wheels 14.

Referring now to the steering axle system 22, in one embodiment, the steering axle system 22 comprises a pair of actuators 52A, 52B (collectively, actuators 52), a pair of rear wheel attachments, including a pair of forks 54A, 54B (collectively, forks 54), a controller 50B, and an axle 56. As indicated above, though shown and described using a pair of forks 54, in some embodiments, a pair of formed spindles may be used for the rear wheel attachments, such as those used in the WR9800 Series SP Massey Ferguson windrowers. In such embodiments, each caster wheel 16 is positioned directly beneath (or substantially directly beneath) the axis of rotation. In some embodiments, the steering axle system 22 may comprise additional or fewer components. The axle 56 extends transverse to a longitudinal axis of the windrower 10, and has opposing ends to which the forks 54A, 54B are respectively coupled. Focusing on the steering axle system 22 for the right hand side of the windrower 10 (with the understanding that the structure and function described for the right hand side of the windrower 10 is similarly applicable to the left hand side), and with reference to FIGS. 1 and 2A, the fork 54B straddles and is coupled to the wheel 16 and also to a gear set 58 (the gear set schematically shown in FIG. 2A). For instance, the gear set 58 may be comprised of plural gears, each of a different size (e.g., different radius), to provide a desired gear ratio. In some embodiments, at least one of the gears of the gear set 58 may be a partial gear (e.g., half, quarter, third, etc.) to reduce weight. In some embodiments, the gear set 58 may be replaced with a crank arm assembly (e.g., bellcrank) or other known mechanisms for translating the rotational motion of a rotary actuator 52B-1 (e.g., a hydraulic cylinder where the rod and core are splined) to the rotation the fork 54B (and hence the same or proportional rotation of the wheel 16). The rotary actuator 52B-1 in turn is coupled to the axle 56. In one embodiment, coupling between the rotary actuator 52B-1 and the axle 56 may be achieved via a flange, threaded connection, or other known attachment mechanisms. The rotary actuator 52B-1 may be provided by one of a plurality of different manufacturers, including Helac rotary actuators, and though depicted as a hydraulic-type rotary actuator, other types of rotary actuators may be used, including pneumatic, electric, magnetic, or electromagnetic type actuators. As indicated above, the rotation provided by the rotary actuators 52B-1 (and hence the wheel rotation) may be in an angular range of zero to one hundred-eighty degrees, or in some embodiments, a greater range (e.g., infinite or three hundred-sixty degrees rotational range).

As is best shown in FIG. 1, the wheels 16 are centered beneath the axle 56. In other words, from an overhead plan view, the wheel 16 has an equal or substantially equal amount of area exposed fore and aft of the axle 56. Note that in embodiments with a different axle design, the vertical axis of rotation may be located slightly forward or aft of the axle. In some embodiments, and referring to FIGS. 1 and 2B, the actuator 52B-2 may be comprised of a rod and piston type actuator (e.g., a linear hydraulic cylinder, though not limited as such) that is oriented in parallel or substantially parallel relationship to a longitudinal axis of the axle 56, though not limited to a parallel orientation. Again, the actuator 52B-2 may engage a gear set 58 or crank assembly to cause rotation (e.g., one hundred-eighty degrees) of the fork 54B (and hence rotation of the wheel 16). Similar to the rotary actuator 52B-1, the linear actuator 52B-2 may be embodied as hydraulic, pneumatic, electric, magnetic, or electromagnetic type actuators. In some embodiments, the actuators 52 may be replaced with a motor that engages the gear set 58 (or crank assembly) directly.

In one embodiment, and particularly for fluid-type (e.g., hydraulic-type) actuators, control of the actuators 52 may be achieved via the controller 50B in cooperation with one or more manifolds 60 (one shown). Note that the location of the manifold 60 depicted in FIG. 1 is illustrative of one example, and that in some embodiments, the manifold(s) 60 may be located elsewhere (e.g., integrated with the assembly associated with the respective caster wheels 16). Also, in some embodiments, the manifold 60 may be omitted and control achieved directly via the controller 50B (e.g., for electric, magnetic, or electromagnetic-type actuators or motors). The manifold 60 comprises one or more control valves (e.g., electric, though not limited as such, and may have other sources of energy for control in some embodiments) that control the flow of hydraulic fluid into and out of ports of the actuators 52 via hydraulic fluid lines, including hydraulic fluid line 62. The manifold 60 is operably coupled to the controller 50B, the latter providing commands to the control valves in the manifold 60 based on input from any one or a combination of the controller 50A, the steering wheel and/or FNR lever in the cab, or one or more sensors. In some embodiments, functionality of the controller 50B may be integrated with the controller 50A, such that commands are provided to the control valves in the manifold 60 via the controller 50A. As would be appreciated by one having ordinary skill in the art, the manifold 60 is also fluidly coupled to a hydraulic pump (P) and reservoir (not shown). Focusing again on the steering axle system 22 located on the right hand side of the windrower 10 (with the same or similar applicability to the left hand side, the description of the same omitted here for brevity), in one embodiment, the actuator 52B (when embodied as a fluid power-type actuator) comprises known internal components that cause movement of the gear set 58 (or crank assembly) based on changes in differential pressure caused by the controller 50B and the control valves of the manifold 60 that receive commands from the controller 50B. For instance, the actuator 52B may comprise a linear piston and cylinder mechanism geared (e.g., via rack and pinion) to produce rotation, or may comprise a rotating asymmetrical vane that swings through a cylinder of two different radii. The differential pressure between the two sides of the vane gives rise to an unbalanced force and thus a torque on an output shaft that couples to the gear set 58 (or crank assembly). In non-rotary-type fluid-powered actuators, the actuator 52B may comprise a piston (or plural pistons in some embodiments) that slides back and forth within the housing of the actuator 52B based on hydraulic fluid displacement, as triggered and controlled by the control valves of the manifold 60 and conveyed over the hydraulic fluid lines 62. The actuator 52B may also comprise a rod that is coupled to, and moves synchronously with, the internal piston, which directly causes the gear set 58 (or crank assembly) to pivot or rotate (e.g., enabling rotation to the left and right) the fork 54B and hence the rear (right) caster wheel 16. In some embodiments, a sensor 64 (represented diagrammatically by a triangle, with a like sensor shown on the left hand side proximal to or integrated with the actuator 52A) may be used to sense the position of the caster wheel 16 (e.g., the steer-position), providing feedback to the controller 50B. In some embodiments, the sensor 64 may be located elsewhere to sense (directly or indirectly) the angle of the rear caster wheels 16. The controller 50B, in turn, provides commands to the control valve(s) of the manifold 60 based on the feedback from the sensor 64, enabling precise adjustment of the fluid displacement over the hydraulic fluid lines 62 into and out of the actuator 52B to enable a controlled or active adjustment of the steering position of the caster wheel 16. As noted above, a similar description applies to the left hand side caster wheel 16.

In one embodiment, software in the controller 50A provides for control of the ground drive system 26, including the dual-path steering system 20, and software in the controller 50B provides control for the steering axle system 22. In general, the caster wheels 16 operate according to a steer-rotation that is actively controlled while the dualpath steering is operational (e.g., both when operating according to zero-radius turns and all other steering or ground travel). Steering actions are coordinated between both the dual-path steering system 20 and the steering axle system 22. In one embodiment, a signal corresponding to a sensed steering wheel and/or FNR lever action is received at the controller 50A and translated into the appropriate magnitude (e.g., speed) and direction of rotation for controlling the front drive wheels 14. A signal sensing the steering wheel and/or FNR lever action may also be received at the controller 50B to enable the controller 50B to translate the steering wheel and/or FNR lever action into corresponding and respective steer commands (e.g., angles of steer) for the actuators 52 to enable adjustment to the appropriate steer angle for each of the rear caster wheels 16. In some embodiments, the controller 50A may determine all desired steer angles and communicate (e.g., via wired or wireless communication) the steer angles to the controller 50B. In some embodiments, the controller 50A may determine the required front wheel steer adjustment and communicate the adjustment to the controller 50B to enable determination by the controller 50B of the appropriately matched (e.g., see FIGS. 3A-3H) rear wheel steer adjustment. As indicated previously, functionality of the controllers 50A and 50B may be combined into a single controller (e.g., controller 50A).

According to the invention, the windrower 10 may tow a pull-type mower conditioner 22 in rough filed conditions to augment the capacity and efficiency of the windrower 10. An appropriate PTO and auxiliary hydraulic connection is supplied by the windrower 10 to the pull-type mower conditioner 22. The pull-type mower conditioner 22 can be removed from the windrower 10 at any time the additional cutting capacity is not needed.

In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment”, “an embodiment”, or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the present technology can include a variety of combinations and/or integrations of the embodiments described herein. Although the control systems and methods have been described with reference to the example embodiments illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the disclosure as protected by the following claims.

Claims (2)

At least the following is claimed:

1. A method implemented in a machine, the method comprising: in a first steering mode, causing a left drive wheel and a right drive wheel to concurrently rotate, wherein the rotation of the left drive wheel is in a direction opposite that of the rotation of the right drive wheel; in a second steering mode non-overlapping in operation with the first steering mode, causing the left drive wheel and the right drive wheel to rotate concurrently in only a same direction; and enabling one or more tailwheel casters to freely steer-rotate during the first steering mode and to steer-rotate according to a limited arc in the second steering mode, the steer-rotation of the tailwheel caster enabled over a wider arc range in the first steering mode than in the second steering mode.

2. A windrower machine operable in two steering modes selectable by an operator of the machine, the dual steering modes being a dual-path steering mode and a tailwheel steering mode, the two steering modes being mutually exclusive, the machine comprising: a chassis; an engine mounted on the chassis; plural drive wheels coupled to the chassis; a ground drive system comprising plural wheel motors and plural hydraulic wheel propel pumps coupled to a respective one of the plural drive wheels, the hydraulic wheel propel pumps being powered by the engine and each wheel motor being powered by its respective hydraulic wheel propel pump; plural tailwheel caster assemblies coupled to opposing sides of the chassis, each tailwheel caster assembly comprising: a tailwheel caster; a sensor; a steering cylinder configured to operably control a steering position of the tailwheel caster when in the tailwheel steering mode; a user interface comprising a steering wheel and a forward-neutral- reverse (FNR) lever operable to control the ground drive system, the FNR lever having a forward position, a neutral position and a reverse position; and a controller configured to selectably operate the ground drive system in either the dual path steering mode or in the tailwheel steering mode: wherein in the dual-path steering mode, the ground drive system drives the plural drive wheels in either the same direction or in the opposite direction of rotation relative to each other depending on the position of the steering wheel and FNR lever, and the position of tailwheel casters are not controlled by the steering cylinders but are permitted unconstrained rotation, and wherein in the tailwheel steering mode, the ground drive system drives the plural drive wheels only in the same direction of rotation and being incapable of counter rotation, and the steering cylinder provides controlled and limited steer-rotation of the tailwheel caster based in part on tailwheel caster steer position information received from the sensor.