Agricultural baler with auxiliary power system powered by movable component(s) on the baler

An agricultural baler includes a flywheel, a driveline associated with the flywheel and couplable with a power take-off (PTO) of a traction unit, and a movable component which is driven directly or indirectly by the driveline and movable in a linear and/or rotational manner. The baler further includes an auxiliary power system coupled with the movable component. The auxiliary power system is configured for receiving power from the movable component and storing the power.

CROSS REFERENCE TO RELATED APPLICATION

This application is the National Stage of International Application No. PCT/EP2015/065474 filed Jul. 7, 2015, which claims priority to Belgium Patent Application No. 2014/0543 filed Jul. 9, 2014, the contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to agricultural balers, and, more particularly, to systems for powering such balers.

DESCRIPTION OF THE RELATED ART

Agricultural harvesting machines, such as balers, are used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. In the case of hay, a mower-conditioner is typically used to cut and condition the crop material for windrow drying in the sun. In the case of straw, an agricultural combine discharges non-grain crop material from the rear of the combine defining the straw (such as wheat or oat straw) which is to be picked up by the baler. The cut crop material is typically raked and dried, and a baler, such as a large square baler or round baler, straddles the windrows and travels along the windrows to pick up the crop material and form it into bales.

On a large square baler, a pickup unit at the front of the baler gathers the cut and windrowed crop material from the ground. The pickup unit includes a pickup roll, and optionally may include other components such as side shields, stub augers, wind guard, etc.

A packer unit is used to move the crop material from the pickup unit to a duct or pre-compression chamber. The packer unit forms a wad of crop within the pre-compression chamber which is then transferred to a main bale chamber. (For purposes of discussion, the charge of crop material within the pre-compression chamber will be termed a “wad”, and the charge of crop material after being compressed within the main bale chamber will be termed a “flake”). Typically such a packer unit includes packer tines or forks to move the crop material from the pickup unit into the pre-compression chamber. Instead of a packer unit it is also known to use a rotor cutter unit which chops the crop material into smaller pieces.

A stuffer unit transfers the wad of crop material in charges from the pre-compression chamber to the main bale chamber. Typically such a stuffer unit includes stuffer forks which are used to move the wad of crop material from the pre-compression chamber to the main bale chamber, in sequence with the reciprocating action of a plunger within the main bale chamber.

In the main bale chamber, the plunger compresses the wad of crop material into flakes to form a bale and, at the same time, gradually advances the bale toward the outlet of the bale chamber. The plunger reciprocates, back and forth, toward and away from the discharge end of the baler. The plunger may include a number of rollers which extend laterally outward from the sides of the plunger. The rollers on each side of the plunger are received within a respective plunger slot formed in the side walls of the bale chamber, with the plunger slots guiding the plunger during the reciprocating movements.

When enough flakes have been added and the bale reaches a full (or other predetermined) size, a number of knotters are actuated which wrap and tie twine, cord or the like around the bale while it is still in the main bale chamber. The twine is cut and the formed baled is ejected out the back of the baler as a new bale is formed.

During a compression cycle of the plunger as described above, the plunger moves through a compression stroke as it advances into the main bale chamber, with the highest load on the plunger occurring at the end of each compression stroke. As balers become increasingly larger, the peak loads on the plunger during compression strokes likewise become increasingly larger. One way to compensate for these higher peak loads is to use a larger flywheel coupled with a gearbox which drives the plunger. As the plunger reaches the end of the compression stroke, the momentum of the heavier flywheel helps carry the plunger through the peak load at the end of the compression stroke. If the flywheel is not heavy enough then high loads are transferred back through the driveline to the base unit, which can result in lugging down of the engine onboard the base unit. However, a flywheel which is too large is also undesirable since it typically requires a base unit with a larger horsepower (HP) rating to start and drive the flywheel forming part of the driveline of the baler.

US 2010/0108413 describes a baler having a jog drive system drivingly connected within the primary drive system. This jog drive system serves as a source of power to the various performance systems in the baler when movement of components within the baler is required for maintenance or adjustment. The jog drive system comprises a jog motor which can be in the form of a hydraulic motor, an electric motor or other suitable drive mechanism for slowly rotating the flywheel of the baler and thereby advancing all performance systems. The jog motor can be connected to a hydraulic system of the tractor, to an electric system of the tractor or can be provided with other sources of power input. This jog drive system is foreseen to assist the operator when maintenance or adjustment is needed to the baler, and does not have an impact on the operation of the plunger, since the jog drive system is only able to slowly rotate the flywheel.

In EP 1 974 601, a similar auxiliary drive is foreseen which functions as a starting arrangement acting on the main drive of the baler and which is capable of acting as a sole drive of the baler or as a drive assisting the main drive in the first phase of the process of starting the baler. During the starting process, the main drive will accelerate to a higher speed than the auxiliary drive by means of a freewheel arrangement, whereupon the auxiliary drive ceases to have any effect on the remainder of the starting process. This auxiliary drive is used to overcome the problem that sometimes it is difficult to start up the baler and will assist only during this start-up phase, after which it ceases to have any effect.

What is needed in the art is an agricultural baler which accommodates large intermittent loads during operation of the baler.

SUMMARY OF THE INVENTION

The present invention provides an agricultural baler with an auxiliary power system (APS) which scavenges power from a rotationally or linearly movable component of the baler and stores the power for subsequent use.

The invention in one form is directed to an agricultural baler including a flywheel, a driveline associated with the flywheel and couplable with a power take-off (PTO) of a fraction unit, and a movable component which is driven directly or indirectly by the driveline and movable in a linear and/or rotational manner. The baler is characterized by an auxiliary power system coupled with the movable component. The auxiliary power system is configured for receiving power from the movable component and storing the power.

An advantage of the present invention is that power is scavenged from at least one movable component which is directly or indirectly driven by the driveline of the baler.

Another advantage is that the power can be scavenged/harvested during off-peak load periods of the plunger duty cycle.

Yet another advantage is that the stored power can be used for various purposes, such as being transmitted back to the driveline to flatten out the load requirements on the driveline, or used to power auxiliary components such as lights, fans, motors, processors, etc.

A further advantage is that the energy from the movable components(s) is captured in the form of stored energy, and thereby avoids heat generation onboard the baler.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly toFIG. 1, there is shown a perspective cutaway view showing the internal workings of a large square baler10. Baler10operates on a two stage feeding system. Crop material is lifted from windrows into the baler10using a pickup unit12. The pickup unit12includes a rotating pickup roll14with tines16which move the crop rearward toward a packer unit18. An optional pair of stub augers (one of which is shown, but not numbered) are positioned above the pickup roll14to move the crop material laterally inward. The packer unit18includes packer tines20which push the crop into a pre-compression chamber22to form a wad of crop material. The packer tines20intertwine the crop together and pack the crop within the pre-compression chamber22. Pre-compression chamber22and packer tines20function as the first stage for crop compression. Once the pressure in the pre-compression chamber22reaches a predetermined sensed value, a stuffer unit24moves the wad of crop from the pre-compression chamber22to a main bale chamber26. The stuffer unit24includes stuffer forks28which thrust the wad of crop directly in front of a plunger30, which reciprocates within the main bale chamber26and compresses the wad of crop into a flake. Stuffer forks28return to their original stationary state after the wad of material has been moved into the main bale chamber26. Plunger30compresses the wads of crop into flakes to form a bale and, at the same time, gradually advances the bale toward outlet32of main bale chamber26. Main bale chamber26and plunger30function as the second stage for crop compression. When enough flakes have been added and the bale reaches a full (or other predetermined) size, knotters34are actuated which wrap and tie twine around the bale while it is still in the main bale chamber26. Needles36bring the lower twine up to the knotters34and the tying process then takes place. The twine is cut and the formed bale is ejected from a discharge chute38as a new bale is formed.

Plunger30is connected via a crank arm40with a gear box42. Gear box42is driven by a flywheel44, which in turn is connected via a drive shaft46with the power take-off (PTO) coupler48. The PTO coupler48is detachably connected with the PTO spline at the rear of the traction unit, such as a tractor (not shown). PTO coupler48, drive shaft46and flywheel44together define a portion of a driveline50which provides rotative power to gearbox42. Flywheel44has a sufficient mass to carry plunger30through a compression stroke as power is applied to drive shaft46by the traction unit. Without the flywheel, a large mechanical load (impulse) is placed on the traction unit as peak power is required by the baler during operation, such as at the end of a compression stroke and/or during a stuffer unit stroke. Generally speaking, as balers become increasingly larger the size of the flywheel also becomes increasingly larger. A larger flywheel also in turn typically requires the use of a traction unit with a higher horsepower rating, to maintain input power to the drive shaft46during operation, and since higher power is required to start rotation of the flywheel from an at-rest position.

Referring now toFIGS. 1-3, conjunctively, baler10also includes an auxiliary power system (APS)52which is coupled with the driveline50in parallel with the flywheel44, in a mechanical power distribution sense and not necessarily a geometric sense. The APS52generally functions to receive power from the driveline50, store the power, and transmit the stored power back to the driveline50.

APS52generally includes a power generation device54for receiving power from the driveline50and generating power, a power storage device56coupled with and storing power from the power generation device54, and a power feedback device58for transmitting the stored power back to the driveline. In the block diagram shown inFIG. 3, the power generation device54and the power feedback device58are configured as the same unit which can operate with different functionality, such as a hydraulic pump/motor or an electric motor/generator. When configured as a hydraulic pump/motor, the power storage device56can be in the form of one or more hydraulic accumulators. Alternatively, when configured as an electric motor/generator, the power storage device56can be in the form of one or more ultracapacitors and/or batteries. With this type of dual functionality, the power storage device56is connected with the power generation device54/power feedback device58in a bidirectional manner allowing 2-way flow of power, as indicated by double headed arrow60.

Alternatively, the power generation device54and the power feedback device58can be separate and discrete units which are each coupled with the driveline50and power storage device56. For example, the power generation device54can be in the form of a hydraulic pump, and the power feedback device58can be in the form of a separate hydraulic motor, each of which are mechanically coupled with the driveline50and hydraulically coupled with a power storage device in the form of an accumulator (not specifically shown). Moreover, the power generation device54can be in the form of an electric motor, and the power feedback device58can be in the form of a separate electric generator, each of which are mechanically coupled with the driveline50and electrically coupled with a power storage device56in the form of an ultracapacitor and/or battery (not specifically shown).

The power storage device56shown inFIG. 3can also be configured differently than one or more hydraulic accumulators, ultracapacitors and/or batteries. For example, the power storage device56can be configured as an additional mechanical flywheel which receives/transmits power from/to the driveline50. The power generation device54and the power feedback device58can be configured as a continuously variable transmission (CVT), and the additional flywheel would somehow be capable of receiving and storing power during off-peak load periods and transferring the power back to the driveline50for use during peak load periods.

For purposes of discussion hereinafter, it will be assumed that the power generation device54and the power feedback device58are in the form of a singular unit configured as a hydraulic pump/motor. Pump/motor54,58is coupled with and under the control of an electrical processing circuit62, which can be in the form of an electronic control unit (ECU) or an analog processor. Electrical processing circuit62can be a dedicated ECU onboard the baler10, or can also be part of an ECU used for other purposes onboard the baler10. Alternatively, electrical processing circuit62can also be an ECU onboard the traction unit which tows the baler10, and can be coupled with the pump/motor54,58and other components onboard baler10in a wired or wireless manner.

Electrical processing circuit62controls operation of pump/motor54,58in a manner such that power is transmitted to the driveline50prior to and during peak load periods on the baler10, and power is received from the driveline50during off-peak load periods on the baler10. More specifically, power is transmitted to/from the driveline50dependent upon a position of the plunger30within the main bale chamber26, and/or a variable associated with the formation of a slice of crop material within the bale chamber26. To this end, the electrical processing circuit62is connected with one or more sensors64which provide output signals indicative of the position of the plunger30and/or a crop slice variable. In the embodiment shown inFIG. 3, the sensor64is positioned adjacent to flywheel44to determine the rotational position of the flywheel44, such as by using a proximity sensor, optical sensor, etc. The position of the flywheel44can in turn be used to establish the position of the plunger30within the main bale chamber26. Alternatively, the sensor64can be configured to sense a variable associated with crop slice formation within the main bale chamber26. Examples of crop slice formation variables may include a moisture content of the crop material, a thickness of a given slice of crop material and/or a positional change of the plunger at maximum compression for each slice of the crop material. Alternatively, the variable associated with the crop slice formation can even be input by a user, such as a particular type of crop material being harvested. Other input variables may also be used for controlling operation of APS52.

Referring now toFIG. 4, there is shown a control schematic of the APS52shown inFIGS. 1-3. APS52can be thought of as defining a hydraulic flywheel which is based on an over-center variable displacement pump/motor54,58connected between the accumulator56and a tank66. In order to avoid any overpressure, a pressure relief valve68is installed between the pump/motor54,58and the accumulator56. A check valve70is also connected to the tank66in order to avoid cavitation of the pump/motor54,58. A pressure transducer72is used to manage the displacement of the pump/motor54,58. Basically, during a typical duty cycle, the pump/motor54,58works as a real pump charging the accumulator56when the instant power of the baler10is lower than the average power (FIG. 5). On the other hand, when the plunger30is in a compressing stroke, the pump/motor54,58works as a motor converting hydraulic power into mechanical power that can be provided to the driveline50. In this way, the typical peak power can be avoided and the PTO power provided from the tractor is always close to the average power. The pump size is a function of the maximum pressure in the accumulator56and the operating speed of the pump/motor54,58. Because of the additional gearbox74coupled with the driveline50, the pump speed can be increased, e.g., from 1000 RPM (the typical PTO speed during working conditions) up to approximately 2680 RPM. This higher speed allows the use of a smaller pump with a higher hydraulic efficiency and faster response time, in contrast with a larger pump needed when operating at a lower speed condition.

According to another aspect of the present invention, the APS52can be connected to and driven by one or more movable components100of baler10other than the driveline50(FIGS. 6 and 7). The baler10includes many other movable components100that move either in an intermittent or continuous basis. Some of these movable components move in a rotational manner, such as drive or driven shafts, while others move in a linear manner, such as the plunger30as it reciprocates within the main bale chamber26. The APS52can harvest energy from these various movable components100and store the energy for specific purposes, such as transferring power back to the driveline50or powering auxiliary components such as lights, fans, motors, etc. onboard the baler10.

In the embodiment shown inFIG. 6, the movable component100is assumed to be a rotatable shaft onboard the baler10, as indicated by direction arrow102. The rotatable shaft can be located at various places on the baler10, such as a rotatable shaft100A associated with the stuffer unit24, a rotatable shaft100B associated with the packer unit18, a rotatable shaft100C associated with the pickup unit12(FIG. 1), or a rotatable shaft100E driven by the crop flow/bale/crop material (such as a shaft associated with a star wheel in the bottom of the main bale chamber26). The baler10can also include other types of rotatable shafts that rotate on a continuous or intermittent basis, and used to drive the APS52.

When configured as a rotatable shaft100, the APS52can include a rotatable power generation device54in the form of a hydraulic motor and/or electric motor which is used to generate power which is then stored in the power storage device56. When the power generation device54is a hydraulic motor then the power storage device can be configured as one or more hydraulic accumulators. When the power generation device54is an electric motor then the power storage device56can be configured as one or more ultracapacitors and/or batteries.

In the embodiment shown inFIG. 7, the movable component100is assumed to be a linearly moving component100D on the baler10, such as the plunger30which reciprocates within the main bale chamber26, as indicated by direction arrow104.

When configured as a linearly movable component100, the APS52can include a linearly movable power generation device54in the form of a hydraulic cylinder assembly106with a piston108which reciprocates within a two-way cylinder110. Pressurized fluid flows through a fluid line112to the hydraulic accumulator62. A check valve114prevents the pressurized fluid from flowing back into the cylinder assembly106on the return stroke of the piston108. The pressurized hydraulic fluid that is stored in the accumulator62can be used for various purposes, such as transferring power via a line116back to the driveline50using a motor58, or powering auxiliary components such as lights, fans, motors, etc via a line118.

The movable component100can also move in both a rotational and translational manner, such as the crank arm40which drives the plunger30. The APS52can be configured to harvest the rotational and/or the translational (i.e., linear) movement of the crank arm40so that power can be generated and stored.

During operation of the baler10, the driveline50drives the gearbox42, which in turn drives the plunger30using the crank arm40. The plunger30reciprocates back and forth during compression cycles within the main bale chamber26. The driveline50also directly or indirectly drives other movable components100onboard the baler10. The APS52can be coupled with and driven by one or more selected movable components100, which can either be rotationally or linearly movable components, as described above. Power from the movable component100is used to drive a power generation device54such as a hydraulic pump, electric motor and/or hydraulic cylinder. The power can be harvested at any time during the movement of the movable component100. In one embodiment, the power is harvested during off-peak load periods of the plunger30and timed in coordination with the duty cycle of the plunger30, as described above with reference toFIGS. 3-5. After the hydraulic and/or electric power is stored in an appropriately configured power storage device56, the power can then be subsequently used for various purposes onboard the baler10. For example, a power feedback device58can be used to transfer power back to the driveline50to flatten out the power requirements of the baler10, or the power can be used to power auxiliary components such as lights, fans, motors, etc.