Hybrid Industrial Machine Powertrain

An industrial machine is provided that includes a hybrid powertrain. The hybrid powertrain includes a PTI/PTO (power-take-in/power-take-off) system that can passively decouple an internal combustion engine from other powertrain components. The hybrid powertrain allows the industrial machine to operate in power delivering modes, in which an internal combustion engine and/or an electric motor(s) are prime movers, a fully electric mode in which the electric motor(s) is the prime mover(s), and power generating modes, in which either the internal combustion engine or load inertia drives the electric motor(s) as an electrical power generator.

BACKGROUND OF THE INVENTION

Field of the Invention

The preferred embodiments relate generally to the field of industrial powertrain systems and, more specifically, to a hybrid industrial powertrain.

Discussion of the Related Art

The electrification and electric hybridization of powertrains is growing increasingly popular. Although numerous prevalent examples can be seen in the automotive industry, numerous challenges exist in the hybridization of power transmission for industrial powertrains of other machines, including off-highway machines, mobile equipment and stationary equipment, such as, for example, cranes and other material handling equipment, wood chippers and other recycling or processing equipment, rock crushers and other construction equipment, and industrial accessory equipment or machines such as municipal and airport industrial snow throwers with auxiliary IC (internal combustion) engines.

Many of these industrial machines have limited space in their powertrain compartments because of practical size constraints for the overall machines, especially those that are mobile. The powertrain compartments must house industrial IC engines, some of which are relatively large with high horsepower ratings of hundreds or more than one thousand horsepower, depending on the particular power requirements for the machines' working systems. Besides the industrial IC engines, the powertrain compartments of these machines also house major components of hydraulic systems and other power transmitting systems that deliver power to the machines' working systems.

Typical electric hybrid powertrain systems have electric motors that are sized or have power ratings based on the size or power rating of the IC engine they compliment. Accordingly, a large industrial IC engine would require a large electric motor as a complimentary prime mover in a hybrid industrial machine powertrain. Not only do large electric motors occupy a lot of space, but they can require high inrush or starting currents to urge the motor begin rotating. Control systems that can manage high inrush starting currents can be complex and expensive.

Typical electric hybrid powertrain systems have master clutches or selectively engageable transmissions for switching between IC engine-powered and electric-powered modes. These extra components add to the overall size of the hybrid powertrain system and add complexity to the control methodology of the hybrid powertrain system.

What is therefore needed is a system that allows for electric hybridization of an industrial machine powertrain that minimizes space occupied by an electric motor and can be implemented with straight-forward and cost-effective controls.

SUMMARY AND OBJECTS OF THE INVENTION

The preferred embodiments overcome the above-noted drawbacks by providing a hybrid industrial machine with a passive clutching system to allow switching between operational modes without requiring active clutch or transmission control and that has its hybrid components housed within substantially the same sized powertrain compartments as a non-hybrid version of the machine. This may be implemented as a hybrid industrial machine powertrain with a one-way clutch integrated in a coupler that directly connects an IC engine and a PTI/PTO (power-take-in/power-take-off) gearbox.

In some implementations, the PTI/PTO gearbox may provide power flow paths for delivering power to a hydraulic system. In such implementations, at least one electric motor and a pump drive may be connected to the PTI/PTO gearbox, downstream of the IC engine. The PTI/PTO gearbox may occupy a relatively small footprint within an engine compartment with a tower configuration that mounts multiple various components such as electric motor(s), pump drive, and/or hydraulic pump(s) to the single tower.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring toFIG.1, one embodiment of the invention is a hybrid powertrain for an industrial machine, shown as machine10. Machine10is typically a heavy-duty or industrial machine powered by a heavy-duty or industrial engine. Machine10may include those that are self-propelled with their own drivetrains such as cranes, mining trucks, logging equipment, material handling equipment, firefighting and other vehicles. Other examples of machines10include those that may be towed or stationary and that are configured to perform work, including, for example, wood chippers and other recycling or processing equipment, rock crushers and other construction equipment, and industrial accessory equipment or machines such as municipal and airport industrial snow throwers.

Still referring toFIG.1, machine10has various cooperating systems, with self-propelled implementations of machine10having drivetrains11, which include vehicle-type chassis and that support hybrid powertrain systems14. Powertrain system14includes an IC engine system16, a hybrid PTI/PTO (power-take-in/power-take-off) system17, and an electrical system18. The power from the hybrid powertrain system14may be delivered through a transmission15to various drivetrain11components for moving the self-propelled machine10, such as driveshafts or propeller shafts that transmit torque to driven axles or other driven components. Other systems, such as working system19, may receive power from transmission15for performing tasks other than propelling the machine10. Instead of or in addition to receiving power from transmission15, working system19may receive power from various components of hybrid powertrain system14.

Still now toFIG.2, working system19may include a tool(s) or component(s)22that is actuated, rotated, or otherwise moved by a drive24and is configured to perform a task(s) that corresponds to the particular type of machine. Examples include winding drum systems, boom control systems, and turret rotating systems for cranes, feed systems and cutting systems for wood chippers, and auger systems, impeller systems, and chute systems for industrial snow throwers.

Still referring toFIG.2, IC engine system16includes an industrial IC engine, shown as engine26that cooperates with the hybrid PTI/PTO system17. The hybrid PTI/PTO system includes a hybrid drive28with a PTI/PTO gearbox30that is connected to and selectively receives power from engine26of the IC engine system16and at least one electric motor(s)40of the electrical system18. Hybrid drive28may deliver power to the working system's drive24by way of, for example, geartrains, rotating shafts, or hydraulic power.

Referring now toFIG.3, hydraulic system20is shown connected to an output end of the PTI/PTO gearbox30by way of pump drive34, which delivers the power to at least one hydraulic pump(s)36that pressurizes hydraulic fluid for use by hydraulic system20. When the working system's drive24includes a hydraulic motor38, the hydraulic pump(s)36is fluidly connected to the hydraulic motor38to rotate the hydraulic motor38to provide actuation, rotation, or other movement to the tool(s) or component(s)22or various accessories of working system19, to perform the machine's work.

Referring now toFIG.4, machine10is substantially the same as that shown inFIG.3, only with a different arrangement of various components in the electrical system18and hydraulic system20. Electric motor40is shown here connected to a main output or through drive of the hybrid PTI/PTO system's PTI/PTO gearbox30and hydraulic pump36is shown as mounted to an auxiliary-type output of the PTI/PTO gearbox30.

Referring now toFIGS.1-4, electrical system18includes at least one electric motor(s)40that is connected to the PTI/PTO gearbox30, as a supplemental prime mover(s), in addition to engine26. A battery42of electrical system18provides a DC power source usable by the electrical system18and is typically implemented as a bank of multiple interconnected cells or batteries, which may include lithium-ion batteries or various lead and electrolyte configurations such as AGM (absorbent glass mat) sealed batteries. When the electric motor(s)40is an AC motor, the electrical system18further includes an inverter and related hardware and corresponding software for converting the DC power from the battery42into AC power for use by the electric motor(s)40. A BMS (battery management system)44is operably connected to battery42. The BMS44typically includes a charger and control components for monitoring and establishing and/or maintaining the battery's42charge state or other performance characteristics. BMS44has circuitry that includes corresponding hardware, firmware, and/or software, as well as conductors or other components for power and data or signal transmission that cooperate to monitor operational parameters of battery42and/or control various system functions to attenuate deviations from acceptable target values or ranges for the battery's42operating parameters, such as temperature, voltage, charge state, and others. BMS44may be implemented as a standalone system that manages battery42or as part of an overall control system, shown here as control system50.

Still referring toFIGS.1-4, control system50may include a controller52such as a computer that executes various stored programs while receiving inputs from and sending commands to control various subsystems or components in the working system19and hybrid power system14and its IC engine system16, electrical system18, and hydraulic system20.

Referring now toFIG.5, within hybrid PTI/PTO system17, an input arrangement60is defined between and connects respective rotating components of the engine26and PTI/PTO gearbox30, shown here as the engine's flywheel62and a coupler64that includes a passive clutch such as a one-way clutch or sprag clutch, represented as clutch66. An output arrangement70is defined between and connects respective rotating components of the PTI/PTO gearbox30and pump drive36, shown here as the PTI/PTO gearbox's output plate72and a coupler74at the pump drive's34input end. The pump(s)36are mounted to an output end of pump drive34. A pair of pump pads80,82are shown at the pump drive's34output end, each supporting multiple hydraulic pumps as a stacked-pump arrangement. Pump stack36A is shown with three pumps84A,86A,88A mounted to pump pad80. Pump stack36B is shown with three pumps84B,86B,88B mounted to pump pad82.

Referring now toFIG.6, PTI/PTO gearbox30is shown defining a tower90with a lower section92that is sandwiched between engine26and pump drive34and an upper section94that extends upwardly from the lower section92and is shown here supporting multiple electric motors as prime movers. A pair of motor adapters96,98are connected to the tower's upper section94and support a pair of electric motors40A,40B.

Referring now toFIG.7, PTI/PTO gearbox30is shown with a two-piece case or housing100, with front housing segment102that faces toward engine26(FIG.6) and rear housing segment104that faces toward pump drive34(FIG.6). The housing100encloses a geartrain110that constantly meshes and includes a main gear112that is splined, keyed, or otherwise mounted for rotation in unison with main shaft114. Intermediate gear116meshes with main gear112and is supported on intermediate shaft118. Upper gear120meshes with intermediate gear116and is splined, keyed, or otherwise mounted for rotation in unison with upper shaft122. Although only one upper gear120and upper shaft122are shown here, it is understood that the number of paired upper gears/shafts corresponds to the number of motors40supported by the tower's upper section94for a particular implementation.

Still referring toFIG.7, coupler64may be a cushion-type coupler, such as a RBD (rubber block drive) coupler that provides a flexible, elastic, or shock-absorbing connection between the engine's flywheel62and the PTI/PTO gearbox's main shaft114. Clutch66is shown as a sprag clutch that interconnects the coupler64to main shaft114, which is configured to allow the main shaft114to overrun the coupler64and correspondingly also the engine's flywheel62. Clutch66has an inner race130that is splined, keyed, or otherwise mounted for rotation in unison main shaft114. An outer race132is provides a mounting structure to which the coupler64is connected, shown here by way of fasteners, so that the outer race132and coupler64are locked into rotational unison with each other. Selectively locking components such as wedges or sprags134are housed between the clutch's inner and outer races130,132so that the sprags the relative rotation of the inner and outer races130,132in one direction is permitted to disengage the races from each other while rotation in the opposite direction wedges the sprags134between the inner and outer races130,132to lock them into rotational unison and transmit torque between the inner and outer races130,132. This allows the main shaft114to rotate at least as fast as the rotation of the flywheel62and coupler64, while allowing the main shaft114to rotate faster than or overrun the flywheel62and coupler64without transmitting torque in that upstream direction.

Still referring toFIG.7, hybrid PTI/PTO system17is able to passively input torque from multiple prime movers, such as engine26(FIG.6), motor40A (FIG.6), and motor40B (FIG.6), individually or in combination(s) for powering hydraulic system20(FIG.5). Furthermore, through geartrain110, besides driving as prime movers, each of the motors40A,40B can be driven as a generator for recharging the battery42(FIG.1). This can be done either by transmitting power from the PTI/PTO system's input to rotate the motor(s)40A,40B as a generator(s) or by transmitting power from the PTI/PTO system's output to rotate the motor(s)40A,40B as a generator(s).

Referring now generally toFIGS.8-21, control system50(FIGS.1-4) controls operation of the motors40A,40B, to place them in different operational modes to achieve the particular performance characteristics of hybrid power system14based on the power delivery and/or power generation needs of machine10(FIGS.1-4).

Referring generally to theFIGS.8-15, various operational states of components or systems are shown that correspond to the modes in which hybrid power system14delivers power, for example, for use by the working system19to act on a load or otherwise perform work, depending on the particular configuration of machine10(FIGS.1-4). Power delivery modes are represented by the arrow(s) directed out of the hybrid power system14, toward load/work12(FIGS.9-15).

Referring now toFIGS.8and9, in one power delivery mode, the hybrid power system14defines an IC engine power delivery mode for performing work with the machine10(FIGS.1-4). In the IC engine power delivery mode, the engine26is active and both of the motors40A,40B are inactive. Referring now toFIGS.8and10-12, in another power delivery mode, the hybrid power system14defines an electric power delivery mode for performing work with the machine10(FIGS.1-4).FIG.10shows only motor40A energized and delivering power. This provides a first single motor full electric mode in which a first one of the pair of electric motors solely provides the power to the working system19(FIGS.1-4).FIG.11shows only motor40B energized and delivering power. This provides a second single motor full electric mode in which the second electric motor solely provides the power to the working system19(FIGS.1-4). FIG.12shows both motors40A,40B energized and delivering power. This provides a dual motor full electric mode in which the pair of electric motors40A,40B simultaneously provides the power to the working system19(FIGS.1-4).

Referring now toFIGS.8and13-15, in another power delivery mode, the hybrid power system14defines a hybrid power delivery mode for performing work with the machine10(FIG.1-4).FIG.13shows engine26and motor40A delivering power. This provides a first single motor hybrid mode in which the IC engine26provides power, with a first one of the electric motors40A providing supplemental power to the working system19(FIGS.1-4).FIG.14shows engine26and motor40B delivering power. This provides a second single motor hybrid mode in which the second electric motor40B provides power to supplement the IC engine's26power, for powering the working system19(FIGS.1-4).FIG.15shows engine26and both motors40A,40B delivering power. This provides a dual motor hybrid mode in which the IC engine26and both of the electric motors40A,40B simultaneously provide power to the working system19(FIGS.1-4).

Referring generally to theFIGS.8and16-21, various operational states of components or systems are shown that correspond to the modes in which hybrid power system14generates power, for example, for use by the electrical system18(FIGS.1-4) to recharge the battery42. Power generation modes are represented by the arrow(s) directed out of the hybrid power system14, toward battery42(FIGS.16-21).

Referring now toFIGS.8and16-18, in one power generation mode, the hybrid power system14is controlled by control system50to use the engine26as a prime mover to drive the motor(s) as a generator(s) to create electrical power, which may be performed as a stand-alone power generation session or while performing work with the working system19(FIG.1-4).FIG.16shows engine26driving motor40A as a generator, which charges battery42. This provides a first single motor/IC engine generator mode in which the IC engine26drives a first one of the pair of electric motors40A to generate electrical power.FIG.17shows engine26driving motor40B as a generator, which charges battery42. This provides a second single motor/IC engine generator mode in which the IC engine26drives the second electric motor40B to generate electrical power.FIG.18shows engine26driving both motors40A,40B as generators, charging battery42. This provides a dual motor/IC engine generator mode in which the IC engine drives both of the first and second motors to generate electrical power.

Referring now toFIGS.8and19-21, in another power generation mode, as a regenerative-type generation mode, the hybrid power system14is controlled by control system50to use the motors40A,40B as regenerative brakes, so that slowing momentum of a load of working system19(FIGS.1-4) drives the motor(s) through an output of the PTI/PTO gearbox30, to rotate them as generators.FIG.19shows load control or slowing of load/work12, using its momentum or energy to drive motor40A as a generator, which charges battery42. This provides a first single motor regenerative mode in which energy from a load12drives a first electric motor40A to generate electrical power.FIG.20shows load control or slowing of load/work12, using its momentum or energy to drive motor40B as a generator, which charges battery42. This provides a second single motor regenerative mode in which energy from a load12drives the second electric motor40B to generate electrical power.FIG.21shows load control or slowing of load/work12, using its momentum or energy to drive both motors40A,40B as generators, charging battery42. This provides a dual motor regenerative mode in which the load12drives motors40A,40B to generate electrical power.