Patent Description:
Such a multiple pump hydraulic system is known from <CIT> which shows a system according to the preamble of claim <NUM>.

The invention relates to a multiple pump hydraulic system for a vehicle according to claim <NUM>.

According to the exemplary embodiment shown in <FIG>, a machine or vehicle, shown as vehicle <NUM>, includes a chassis, shown as frame <NUM>; a body assembly, shown as body <NUM>, coupled to the frame <NUM> and having an occupant portion or section, shown as cab <NUM>; operator input and output devices, shown as operator interface <NUM>, that are disposed within the cab <NUM>; a drivetrain, shown as driveline <NUM>, coupled to the frame <NUM> and at least partially disposed under the body <NUM>; a vehicle braking system, shown as braking system <NUM>, coupled to one or more components of the driveline <NUM> to facilitate selectively braking the one or more components of the driveline <NUM>; a hydraulic system <NUM> for providing hydraulic power to vehicle systems or coupled implements; and a vehicle control system, shown as control system <NUM>, coupled to the operator interface <NUM>, the driveline <NUM>, and the braking system <NUM>. In other embodiments, the vehicle <NUM> includes more or fewer components.

According to an exemplary embodiment, the vehicle <NUM> is an off-road machine or vehicle. In some embodiments, the off-road machine or vehicle is an agricultural machine or vehicle such as a tractor, a telehandler, a front loader, a combine harvester, a grape harvester, a forage harvester, a sprayer vehicle, a speedrower, and/or another type of agricultural machine or vehicle. In some embodiments, the off-road machine or vehicle is a construction machine or vehicle such as a skid steer loader, an excavator, a backhoe loader, a wheel loader, a bulldozer, a telehandler, a motor grader, and/or another type of construction machine or vehicle. In some embodiments, the vehicle <NUM> includes one or more attached implements and/or trailed implements such as a front mounted mower, a rear mounted mower, a trailed mower, a tedder, a rake, a baler, a plough, a cultivator, a rotavator, a tiller, a harvester, and/or another type of attached implement or trailed implement.

According to an exemplary embodiment, the cab <NUM> is configured to provide seating for an operator (e.g., a driver, etc.) of the vehicle <NUM>. In some embodiments, the cab <NUM> is configured to provide seating for one or more passengers of the vehicle <NUM>. According to an exemplary embodiment, the operator interface <NUM> is configured to provide an operator with the ability to control one or more functions of and/or provide commands to the vehicle <NUM> and the components thereof (e.g., turn on, turn off, drive, turn, brake, engage various operating modes, raise/lower an implement, etc.). The operator interface <NUM> may include one or more displays and one or more input devices. The one or more displays may be or include a touchscreen, a LCD display, a LED display, a speedometer, gauges, warning lights, etc. The one or more input device may be or include a steering wheel, a joystick, buttons, switches, knobs, levers, an accelerator pedal, a brake pedal, etc..

According to an exemplary embodiment, the driveline <NUM> is configured to propel the vehicle <NUM>. As shown in <FIG>, the driveline <NUM> includes a primary driver, shown as prime mover <NUM>, and an energy storage device, shown as energy storage <NUM>. In some embodiments, the driveline <NUM> is a conventional driveline whereby the prime mover <NUM> is an internal combustion engine and the energy storage <NUM> is a fuel tank. The internal combustion engine may be a spark-ignition internal combustion engine or a compression-ignition internal combustion engine that may use any suitable fuel type (e.g., diesel, ethanol, gasoline, natural gas, propane, etc.). In some embodiments, the driveline <NUM> is an electric driveline whereby the prime mover <NUM> is an electric motor and the energy storage <NUM> is a battery system. In some embodiments, the driveline <NUM> is a fuel cell electric driveline whereby the prime mover <NUM> is an electric motor and the energy storage <NUM> is a fuel cell (e.g., storing hydrogen, producing electricity from the hydrogen, etc.). In some embodiments, the driveline <NUM> is a hybrid driveline whereby (i) the prime mover <NUM> includes an internal combustion engine and an electric motor/generator and (ii) the energy storage <NUM> includes a fuel tank and/or a battery system.

As shown in <FIG>, the driveline <NUM> includes a transmission device (e.g., a gearbox, a continuous variable transmission ("CVT"), etc.), shown as transmission <NUM>, coupled to the prime mover <NUM>; a power divider, shown as transfer case <NUM>, coupled to the transmission <NUM>; a first tractive assembly, shown as front tractive assembly <NUM>, coupled to a first output of the transfer case <NUM>, shown as front output <NUM>; and a second tractive assembly, shown as rear tractive assembly <NUM>, coupled to a second output of the transfer case <NUM>, shown as rear output <NUM>. According to an exemplary embodiment, the transmission <NUM> has a variety of configurations (e.g., gear ratios, etc.) and provides different output speeds relative to a mechanical input received thereby from the prime mover <NUM>. In some embodiments (e.g., in electric driveline configurations, in hybrid driveline configurations, etc.), the driveline <NUM> does not include the transmission <NUM>. In such embodiments, the prime mover <NUM> may be directly coupled to the transfer case <NUM>. According to an exemplary embodiment, the transfer case <NUM> is configured to facilitate driving both the front tractive assembly <NUM> and the rear tractive assembly <NUM> with the prime mover <NUM> to facilitate front and rear drive (e.g., an all-wheel-drive vehicle, a four-wheel-drive vehicle, etc.). In some embodiments, the transfer case <NUM> facilitates selectively engaging rear drive only, front drive only, and both front and rear drive simultaneously. In some embodiments, the transmission <NUM> and/or the transfer case <NUM> facilitate selectively disengaging the front tractive assembly <NUM> and the rear tractive assembly <NUM> from the prime mover <NUM> (e.g., to permit free movement of the front tractive assembly <NUM> and the rear tractive assembly <NUM> in a neutral mode of operation). In some embodiments, the driveline <NUM> does not include the transfer case <NUM>. In such embodiments, the prime mover <NUM> or the transmission <NUM> may directly drive the front tractive assembly <NUM> (i.e., a front-wheel-drive vehicle) or the rear tractive assembly <NUM> (i.e., a rear-wheel-drive vehicle).

As shown in <FIG> and <FIG>, the front tractive assembly <NUM> includes a first drive shaft, shown as front drive shaft <NUM>, coupled to the front output <NUM> of the transfer case <NUM>; a first differential, shown as front differential <NUM>, coupled to the front drive shaft <NUM>; a first axle, shown front axle <NUM>, coupled to the front differential <NUM>; and a first pair of tractive elements, shown as front tractive elements <NUM>, coupled to the front axle <NUM>. In some embodiments, the front tractive assembly <NUM> includes a plurality of front axles <NUM>. In some embodiments, the front tractive assembly <NUM> does not include the front drive shaft <NUM> or the front differential <NUM> (e.g., a rear-wheel-drive vehicle). In some embodiments, the front drive shaft <NUM> is directly coupled to the transmission <NUM> (e.g., in a front-wheel-drive vehicle, in embodiments where the driveline <NUM> does not include the transfer case <NUM>, etc.) or the prime mover <NUM> (e.g., in a front-wheel-drive vehicle, in embodiments where the driveline <NUM> does not include the transfer case <NUM> or the transmission <NUM>, etc.). The front axle <NUM> may include one or more components.

As shown in <FIG> and <FIG>, the rear tractive assembly <NUM> includes a second drive shaft, shown as rear drive shaft <NUM>, coupled to the rear output <NUM> of the transfer case <NUM>; a second differential, shown as rear differential <NUM>, coupled to the rear drive shaft <NUM>; a second axle, shown rear axle <NUM>, coupled to the rear differential <NUM>; and a second pair of tractive elements, shown as rear tractive elements <NUM>, coupled to the rear axle <NUM>. In some embodiments, the rear tractive assembly <NUM> includes a plurality of rear axles <NUM>. In some embodiments, the rear tractive assembly <NUM> does not include the rear drive shaft <NUM> or the rear differential <NUM> (e.g., a front-wheel-drive vehicle). In some embodiments, the rear drive shaft <NUM> is directly coupled to the transmission <NUM> (e.g., in a rear-wheel-drive vehicle, in embodiments where the driveline <NUM> does not include the transfer case <NUM>, etc.) or the prime mover <NUM> (e.g., in a rear-wheel-drive vehicle, in embodiments where the driveline <NUM> does not include the transfer case <NUM> or the transmission <NUM>, etc.). The rear axle <NUM> may include one or more components. According to the exemplary embodiment shown in <FIG>, the front tractive elements <NUM> and the rear tractive elements <NUM> are structured as wheels. In other embodiments, the front tractive elements <NUM> and the rear tractive elements <NUM> are otherwise structured (e.g., tracks, etc.). In some embodiments, the front tractive elements <NUM> and the rear tractive elements <NUM> are both steerable. In other embodiments, only one of the front tractive elements <NUM> or the rear tractive elements <NUM> is steerable. In still other embodiments, both the front tractive elements <NUM> and the rear tractive elements <NUM> are fixed and not steerable.

In some embodiments, the driveline <NUM> includes a plurality of prime movers <NUM>. By way of example, the driveline <NUM> may include a first prime mover <NUM> that drives the front tractive assembly <NUM> and a second prime mover <NUM> that drives the rear tractive assembly <NUM>. By way of another example, the driveline <NUM> may include a first prime mover <NUM> that drives a first one of the front tractive elements <NUM>, a second prime mover <NUM> that drives a second one of the front tractive elements <NUM>, a third prime mover <NUM> that drives a first one of the rear tractive elements <NUM>, and/or a fourth prime mover <NUM> that drives a second one of the rear tractive elements <NUM>. By way of still another example, the driveline <NUM> may include a first prime mover that drives the front tractive assembly <NUM>, a second prime mover <NUM> that drives a first one of the rear tractive elements <NUM>, and a third prime mover <NUM> that drives a second one of the rear tractive elements <NUM>. By way of yet another example, the driveline <NUM> may include a first prime mover that drives the rear tractive assembly <NUM>, a second prime mover <NUM> that drives a first one of the front tractive elements <NUM>, and a third prime mover <NUM> that drives a second one of the front tractive elements <NUM>. In such embodiments, the driveline <NUM> may not include the transmission <NUM> or the transfer case <NUM>.

As shown in <FIG>, the driveline <NUM> includes a power-take-off ("PTO"), shown as PTO <NUM>. While the PTO <NUM> is shown as being an output of the transmission <NUM>, in other embodiments the PTO <NUM> may be an output of the prime mover <NUM>, the transmission <NUM>, and/or the transfer case <NUM>. According to an exemplary embodiment, the PTO <NUM> is configured to facilitate driving an attached implement and/or a trailed implement of the vehicle <NUM>. In some embodiments, the driveline <NUM> includes a PTO clutch positioned to selectively decouple the driveline <NUM> from the attached implement and/or the trailed implement of the vehicle <NUM> (e.g., so that the attached implement and/or the trailed implement is only operated when desired, etc.).

According to an exemplary embodiment, the braking system <NUM> includes one or more brakes (e.g., disc brakes, drum brakes, in-board brakes, axle brakes, etc.) positioned to facilitate selectively braking (i) one or more components of the driveline <NUM> and/or (ii) one or more components of a trailed implement. In some embodiments, the one or more brakes include (i) one or more front brakes positioned to facilitate braking one or more components of the front tractive assembly <NUM> and (ii) one or more rear brakes positioned to facilitate braking one or more components of the rear tractive assembly <NUM>. In some embodiments, the one or more brakes include only the one or more front brakes. In some embodiments, the one or more brakes include only the one or more rear brakes. In some embodiments, the one or more front brakes include two front brakes, one positioned to facilitate braking each of the front tractive elements <NUM>. In some embodiments, the one or more front brakes include at least one front brake positioned to facilitate braking the front axle <NUM>. In some embodiments, the one or more rear brakes include two rear brakes, one positioned to facilitate braking each of the rear tractive elements <NUM>. In some embodiments, the one or more rear brakes include at least one rear brake positioned to facilitate braking the rear axle <NUM>. Accordingly, the braking system <NUM> may include one or more brakes to facilitate braking the front axle <NUM>, the front tractive elements <NUM>, the rear axle <NUM>, and/or the rear tractive elements <NUM>. In some embodiments, the one or more brakes additionally include one or more trailer brakes of a trailed implement attached to the vehicle <NUM>. The trailer brakes are positioned to facilitate selectively braking one or more axles and/or one more tractive elements (e.g., wheels, etc.) of the trailed implement.

With continues reference to <FIG>, the hydraulic system <NUM> may be driven by the PTO <NUM> (e.g., a belt driven output, a shaft driven output, an electric motor output from an electronic PTO, etc.). In some embodiments, the hydraulic system <NUM> may be directly driven by the prime mover <NUM>, by a secondary prime mover (e.g., an electric machine, an onboard generator set, etc.) or by another portion of the driveline <NUM>.

In some embodiments, the hydraulic system <NUM> includes an electrohydraulic remote (EHR) system <NUM> including six EHR ports <NUM>-<NUM> through <NUM>-<NUM> that may be coupled to external implements. In some embodiments, the vehicle <NUM> includes three EHR ports <NUM>-<NUM> through <NUM>-<NUM>. In some embodiments, the vehicle <NUM> includes more than six EHR ports <NUM>-X or more than six EHR ports <NUM>-X. The EHR system <NUM> can be used to provide selective control and variable hydraulic pressure to each of the EHR ports <NUM>-<NUM> through <NUM>-<NUM>. In some embodiments, each EHR port <NUM>-X includes a manually adjustable lever, screw or other interface that can be used to adjust the pressure provided to the EHR port <NUM>-X. In some embodiments, the pressure provided to each EHR port <NUM>-X can be adjusted via the operator interface <NUM> (e.g., a human machine interface, a touch screen, a joystick, etc.). The EHR system <NUM> also includes a load sense feature including one or more load sense ports. In some embodiments, each EHR port <NUM>-X and each load sensor port includes a sensor or sensor array in communication with the control system <NUM>. For example, each EHR port <NUM>-X and each load sensor port may include a pressure transducer arranged in communication with the control system <NUM>.

In some embodiments, the hydraulic system <NUM> includes a power beyond system <NUM> that provides a full flow of hydraulic power to an external implement coupled to the vehicle <NUM>. In some embodiments, the power beyond system <NUM> includes a first power beyond port <NUM>-<NUM> and a second power beyond port <NUM>-<NUM>. In some embodiments, more than two or less than two power beyond ports <NUM>-X are provided on the vehicle <NUM>. The power beyond system <NUM> may also include a load sense feature including one or more load sense ports. In some embodiments, each power beyond port <NUM>-X and each load sensor port includes a sensor or sensor array in communication with the control system <NUM>. For example, each power beyond port <NUM>-X and each load sensor port may include a pressure transducer arranged in communication with the control system <NUM>.

As shown in <FIG>, the hydraulic system <NUM> shown in <FIG> includes a multiple pump hydraulic system <NUM> including a primary pump <NUM> and a twin or secondary pump <NUM>. In some embodiments, the primary pump <NUM> provides a maximum output of eighty-five cubic centimeters per revolution (<NUM> cc/rev). In some embodiments, the secondary pump <NUM> provides a maximum output of forty-five cubic centimeters per revolution (<NUM> cc/rev).

The primary pump <NUM> and the secondary pump <NUM> can be operated in a combine flow mode and a separate flow mode. In the combined flow mode, also called a serial mode, the primary pump <NUM> and the secondary pump <NUM> work in tandem to provide hydraulic system flow to the EHR system <NUM> and/or the power beyond system <NUM>. In the combined mode, when hydraulic pressure is desired (e.g., as dictated by the load sense system of the EHR system <NUM> and/or the power beyond system <NUM>) both the primary pump <NUM> and the secondary pump <NUM> operate to provide hydraulic fluid flow and power.

In the separate flow mode, also called a parallel mode, the primary pump <NUM> and the secondary pump <NUM> operate independently and the primary pump <NUM> may be used to service a first portion of the hydraulic system <NUM> (e.g., the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>) and the secondary pump <NUM> may be used to service a second portion of the hydraulic system <NUM> (e.g., the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>). In some embodiments, the return flow from the primary pump <NUM> and ports associated with the primary pump <NUM> may combine with return flow from the secondary pump <NUM> and ports associated with the secondary pump <NUM>.

The multiple pump hydraulic system <NUM> provides a user selectable system that operates in the combined flow mode and the separate flow mode. The use of the combined flow mode or the separate flow mode may be desirable based on how the vehicle <NUM> is being used and the ability to switch between the combined flow mode and the separate flow mode improves system efficiencies. Typical tractors are arranged in only one of a combined flow mode or a separate flow mode and it is difficult to switch between. As a result, operators of such vehicles do not switch pump configurations and therefore operate vehicles at reduced efficiencies compared to the multiple pump hydraulic system <NUM>. The multiple pump hydraulic system <NUM> allows for a user to select a desired operational mode and automatically arrange the multiple pump hydraulic system <NUM> to provide either the combined flow mode or the separate flow mode. By enabling the operator to have control of the combined flow mode or the separate flow mode on the go it allows the hydraulic system <NUM> to be more robust for the application the vehicle <NUM> is being used in.

The primary pump <NUM> of the multiple pump hydraulic system <NUM> includes a primary variable displacement pump system <NUM> fluidly coupled to a sump and providing pressurized hydraulic fluid to a primary pressure port <NUM>. The displacement of the primary variable displacement pump system <NUM> is controlled by a primary load sense system <NUM> in fluid communication with a primary load sense port <NUM>. In some embodiments, the primary load sense system <NUM> includes two spool valves, a first primary spool <NUM> and a second primary spool <NUM>, that control operation of a displacement actuator (e.g., a swashplate actuator, etc.). In some embodiments, the primary load sense port <NUM> is fluidly coupled via load sense pilot ports to the first primary spool <NUM> and to the second primary spool <NUM>, and the primary pressure port <NUM> is fluidly coupled via pressure pilot ports to the first primary spool <NUM> and to the second primary spool <NUM>. A pressure differential between the primary pressure port <NUM> and the primary load sense port <NUM> is used to control the displacement of the primary variable displacement pump system <NUM> via the displacement actuator. In some embodiments, the primary load sense system <NUM> includes adjustable spring returns that can be used to tune the pressure differential at which the first primary spool <NUM> and the second primary spool <NUM> switch and thereby the output pressure of the primary variable displacement pump system <NUM>.

The secondary pump <NUM> of the multiple pump hydraulic system <NUM> includes a secondary variable displacement pump system <NUM> fluidly coupled to a sump (e.g., the same sump used by the primary variable displacement pump system <NUM>) and providing pressurized hydraulic fluid to a secondary pressure port <NUM>. The displacement of the secondary variable displacement pump system <NUM> is controlled by a secondary load sense system <NUM> in fluid communication with a secondary load sense port <NUM>. In some embodiments, the secondary load sense system <NUM> includes two spool valves, a first secondary spool <NUM> and a second secondary spool <NUM>, that control operation of a displacement actuator (e.g., a swashplate actuator, etc.). In some embodiments, the secondary load sense port <NUM> is fluidly coupled via load sense pilot port to the first secondary spool <NUM> and to the second secondary spool <NUM>, and the secondary pressure port <NUM> is fluidly coupled via pressure pilot ports to the first secondary spool <NUM> and to the second secondary spool <NUM>. A pressure differential between the secondary pressure port <NUM> and the secondary load sense port <NUM> is used to control the displacement of the secondary variable displacement pump system <NUM> via the displacement actuator. In some embodiments, the secondary load sense system <NUM> includes adjustable spring returns that can be used to tune the pressure differential at which the first secondary spool <NUM> and the second secondary spool <NUM> switch and thereby the output pressure of the secondary variable displacement pump system <NUM>.

A primary load <NUM> is coupled to the primary pressure port <NUM> of the primary pump <NUM>. In some embodiments, the primary load <NUM> includes EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>. In some embodiments, the primary load <NUM> includes other loads, or less loads as desired. For example, the primary load <NUM> may include hydraulic loads of the vehicle <NUM> not related to external implements.

A secondary load <NUM> is coupled to the secondary pressure port <NUM> of the secondary pump <NUM>. In some embodiments, the secondary load <NUM> includes EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>. In some embodiments, the secondary load <NUM> includes other loads, or less loads as desired. For example, the secondary load <NUM> may include hydraulic loads of the vehicle <NUM> not related to external implements.

A common return <NUM> is coupled to the primary load <NUM> and the secondary load <NUM> and returns hydraulic fluid to the sump of the multiple pump hydraulic system <NUM>. In some embodiments, the primary pump <NUM> and the secondary pump <NUM> may include separate sumps, as desired.

A crossover pressure controller <NUM> is coupled between the primary pressure port <NUM> and the secondary pressure port <NUM>. In some embodiments, the crossover pressure controller <NUM> includes a spring return, solenoid actuated, <NUM>-way, <NUM>-position spool valve. In a separate pressure position (shown in <FIG>), flow is inhibited between the primary pressure port <NUM> and the secondary pressure port <NUM>. In a combined pressure position, the solenoid actuates the spool against a bias of the spring return and provides flow between the primary pressure port <NUM> and the secondary pressure port <NUM>. In some embodiments, the spring return biases the crossover pressure controller <NUM> toward the combined pressure position.

A crossover load sense controller <NUM> is coupled between the primary load sense port <NUM> and the secondary load sense port <NUM>. In some embodiments, the crossover load sense controller <NUM> includes a spring return, solenoid actuated, <NUM>-way, <NUM>-position spool valve. In a separate load sense position (shown in <FIG>), flow is inhibited between the primary load sense port <NUM> and the secondary load sense port <NUM>. In a combined load sense position, the solenoid actuates the spool against a bias of the spring return and provides flow between the primary load sense port <NUM> and the secondary load sense port <NUM>. In some embodiments, the spring return biases the crossover load sense controller <NUM> toward the combined load sense position.

A load sense bleed controller <NUM> is coupled to the primary load sense port <NUM>. In some embodiments, the load sense bleed controller <NUM> includes a spring return, solenoid actuated, <NUM>-way, <NUM>-position spool valve. In a separate bleed position (shown in <FIG>), flow is provided between the primary load sense port <NUM> and the common return <NUM> or the sump. In a combined bleed position, the solenoid actuates the spool against a bias of the spring return and inhibits flow between the primary load sense port <NUM> and common return <NUM>. In some embodiments, the spring return biases the load sense bleed controller <NUM> toward the combined bleed position.

In the separate flow mode (shown in <FIG>), the crossover pressure controller <NUM> is arranged in the separate pressure position and flow is inhibited between the primary pressure port <NUM> and the secondary pressure port <NUM>; the crossover load sense controller <NUM> is arranged in the separate load sense position and flow is inhibited between the primary load sense port <NUM> and the secondary load sense port <NUM>; and the load sense bleed controller <NUM> is arranged in the separate bleed position and flow is provided between the primary load sense port <NUM> and the common return <NUM> or the sump. In the separate flow mode, the primary pump <NUM> and the secondary pump <NUM> each regulate and provide the pressure and flow of hydraulic fluid set by the operator, and load sense and load sense bleed operate separately for the primary pump <NUM> and the secondary pump <NUM> with a combined common return <NUM>.

In the combined flow mode, the crossover pressure controller <NUM> is arranged in the combined pressure position and flow is provided between the primary pressure port <NUM> and the secondary pressure port <NUM>; the crossover load sense controller <NUM> is arranged in the combined load sense position and flow is provided between the primary load sense port <NUM> and the secondary load sense port <NUM>; and the load sense bleed controller <NUM> is arranged in the combined bleed position and flow is inhibited between the primary load sense port <NUM> and the common return <NUM> or the sump. In the combined flow mode, the primary pressure port <NUM> and the secondary pressure port <NUM> are coupled (e.g., are equal in pressure), and the primary load sense port <NUM> and the secondary load sense port <NUM> are coupled (e.g., are equal in pressure). The load sense bleed controller <NUM> is blocked so there is a common bleed through the secondary pump <NUM>.

As shown in <FIG>, the hydraulic system <NUM> shown in <FIG> includes a multiple pump hydraulic system <NUM> including a primary pump <NUM> and a twin or secondary pump <NUM>. In some embodiments, the primary pump <NUM> provides a maximum output of eighty-five cubic centimeters per revolution (<NUM> cc/rev). In some embodiments, the secondary pump <NUM> provides a maximum output of forty-five cubic centimeters per revolution (<NUM> cc/rev). The demand of the vehicle <NUM> does not always require the output from all the pumps of the multiple pump hydraulic system <NUM> depending on the work scenario or activities of the vehicle <NUM>. The multiple pump hydraulic system <NUM> mechanically senses when a load (e.g., connected to the EHR system <NUM> or the power beyond system <NUM>) requires more power and which pumps (e.g., the primary pump <NUM> and/or the secondary pump <NUM>) to load in order to complete the required work.

Typical vehicles with a dual pump system maintain a margin of pressure delta between a pressure port and a load sense port in order for a pressure compensator to operate the load sense function of the system pumps. The margin of pressure delta is directly related to an efficiency of the pump system. The multiple pump hydraulic system <NUM> includes additional features beyond a typical pressure compensator and load sense system thereby making the multiple pump hydraulic system <NUM> more efficient and improving fuel economy of the vehicle <NUM>.

The primary pump <NUM> of the multiple pump hydraulic system <NUM> includes a primary variable displacement pump system <NUM> fluidly coupled to a sump and providing pressurized hydraulic fluid to a primary pressure port <NUM>. The displacement of the primary variable displacement pump system <NUM> is controlled by a primary load sense system <NUM> in fluid communication with a primary load sense port <NUM>. In some embodiments, the primary load sense system <NUM> includes two spool valves, a first primary spool <NUM> and a second primary spool <NUM>, that control operation of a displacement actuator (e.g., a swashplate actuator, etc.) primary variable displacement pump system <NUM>. In some embodiments, the primary load sense port <NUM> is fluidly coupled via a load sense pilot port to the first primary spool <NUM>, and the primary pressure port <NUM> is fluidly coupled via pressure pilot ports to the first primary spool <NUM> and to the second primary spool <NUM>.

In some embodiments, the first primary spool <NUM> is a dual pilot, spring biased, three-position, four-way spool valve and includes: a first position (e.g., leftmost in <FIG>) that sends a destroke signal (e.g., a destroke hydraulic pressure) to both the primary pump <NUM> and the secondary pump <NUM>; a second position (e.g., center in <FIG>) that sends the destroke signal (e.g., the destroke hydraulic pressure) to only the secondary pump <NUM>; and a third position (e.g., rightmost in <FIG>) that inhibits the destroke signal (e.g., does not supply the destroke hydraulic pressure) to the primary pump <NUM> and the secondary pump <NUM> (e.g., both the primary pump <NUM> and the secondary pump <NUM> are at full stroke).

In some embodiments, the second primary spool <NUM> is a dual pilot, spring biased, two-position, three-way spool valve and includes a first position (e.g., leftmost in <FIG>) that destrokes the primary pump <NUM>; and a second position (e.g., rightmost in <FIG>) that provides full stroke of the primary pump <NUM>.

A pressure differential between the primary pressure port <NUM> and the primary load sense port <NUM> is used to control the displacement of the primary variable displacement pump system <NUM> via the displacement actuator. In some embodiments, the primary load sense system <NUM> includes adjustable spring returns that can be used to tune the pressure differential at which the first primary spool <NUM> and the second primary spool <NUM> switch and thereby the output pressure of the primary variable displacement pump system <NUM>.

The secondary pump <NUM> of the multiple pump hydraulic system <NUM> includes a secondary variable displacement pump system <NUM> fluidly coupled to a sump (e.g., the same sump used by the primary variable displacement pump system <NUM>) and providing pressurized hydraulic fluid to a secondary pressure port <NUM>. The displacement of the secondary variable displacement pump system <NUM> is controlled by a secondary load sense system <NUM> in fluid communication with a secondary load sense port <NUM>. In some embodiments, the secondary load sense system <NUM> includes three spool valves, a first secondary spool <NUM> a second secondary spool <NUM>, and a power management spool <NUM>, that control operation of a displacement actuator (e.g., a swashplate actuator, etc.) of the secondary variable displacement pump system <NUM>. In some embodiments, the secondary load sense port <NUM> is fluidly coupled via load sense pilot ports to the first secondary spool <NUM> and to the second secondary spool <NUM>, and the secondary pressure port <NUM> is fluidly coupled via pressure pilot ports to the first secondary spool <NUM> and to the second secondary spool <NUM>.

The first secondary spool <NUM> is a dual pilot, spring biased, three-way, two-position spool valve and includes a first position (e.g., leftmost in <FIG>) that provides a full stroke of the secondary pump <NUM>, and a second position (e.g., rightmost in <FIG>) that destrokes the secondary pump <NUM>.

The second secondary spool <NUM> is a is a dual pilot, spring biased, three-way, two-position spool valve and includes a first position (e.g., leftmost in <FIG>) that provides a full stroke of the secondary pump <NUM>, and a second position (e.g., rightmost in <FIG>) that destrokes the secondary pump <NUM>.

The power management spool <NUM> is a solenoid operated, spring biased, three-way, two-position spool valve and includes a first position (e.g., leftmost in <FIG>) that provides an independent operating mode where the first primary spool <NUM> and the second primary spool <NUM> control load sense operations for the primary pump <NUM> and the first secondary spool <NUM> and the second secondary spool <NUM> control load sense operations for the secondary pump <NUM>. In some embodiments, the spring bias provides a normal operating position in the first position and the solenoid is arranged to overcome the spring bias when energized. The power management spool <NUM> also includes a second position (e.g., rightmost in <FIG>) that provides a power management mode where the first secondary spool <NUM> is isolated and the destroke signal (e.g., the destroke hydraulic pressure) is provided from the first primary spool <NUM> to the second secondary spool <NUM> via the power management spool <NUM>, thereby providing load sense operations for the secondary pump <NUM> that are dictated by the primary load sense system <NUM> of the primary pump <NUM>.

When the secondary load sense system <NUM> is operating in the independent operating mode, a pressure differential between the secondary pressure port <NUM> and the secondary load sense port <NUM> is used to control the displacement of the secondary variable displacement pump system <NUM> via the displacement actuator. In some embodiments, the secondary load sense system <NUM> includes adjustable spring returns that can be used to tune the pressure differential at which the first secondary spool <NUM> and the second secondary spool <NUM> switch and thereby the output pressure of the secondary variable displacement pump system <NUM>.

A primary load <NUM> is coupled to the primary pressure port <NUM> of the primary pump <NUM>. In some embodiments, the primary load <NUM> includes EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>. In some embodiments, the primary load <NUM> includes base loads (e.g., steering, brakes, regulated circuit, etc.), more loads, or less loads, as desired. For example, the primary load <NUM> may include base hydraulic loads of the vehicle <NUM> not related to external implements.

A destroke controller <NUM> is coupled between the primary pressure port <NUM> and the displacement actuator (e.g., a swashplate actuator, etc.) of the secondary variable displacement pump system <NUM>. The destroke controller <NUM> includes a spring return, solenoid actuated two-way, two-position spool valve. When the solenoid is energized, the spool is pushed against the bias of the return spring into a destroked position and flow is provided from the pressurized output of the primary pump <NUM> via the primary pressure port <NUM> to the displacement actuator of the secondary variable displacement pump system <NUM> such that the secondary pump <NUM> is destroked. When the solenoid is not energized, the spring bias moves the spool into an isolated position (as shown in <FIG>) and flow is inhibited between the pressurized output of the primary pump <NUM> via the primary pressure port <NUM> to the displacement actuator of the secondary variable displacement pump system <NUM> such that the stroke of the secondary pump <NUM> is controlled via the secondary load sense system <NUM>. In some embodiments, the destroking controller can normally be in the destroking position, or be actuated in a different way.

In operation, the primary pump <NUM> and the secondary pump <NUM> of the multiple pump hydraulic system <NUM> can be operated in a combine flow mode, a power management combined flow mode, a separate flow mode, and a destroked separate flow mode. The use of the combine flow mode, the power management combined flow mode, the separate flow mode, and/or the destroked separate flow mode may be desirable based on how the vehicle <NUM> is being used, and the ability to switch modes improves system efficiencies. The multiple pump hydraulic system <NUM> allows for a user to select a desired operational mode and automatically arrange the multiple pump hydraulic system <NUM>.

In the combined flow mode, also called a serial mode, the primary pump <NUM> and the secondary pump <NUM> work in tandem to provide hydraulic system flow to the EHR system <NUM> and/or the power beyond system <NUM>. In the combined flow mode, when hydraulic pressure is desired (e.g., as dictated by the load sense system of the EHR system <NUM> and/or the power beyond system <NUM>) both the primary pump <NUM> and the secondary pump <NUM> may be operated to provide hydraulic fluid flow and power. In the combined flow mode, the crossover pressure controller <NUM> is arranged in the combined pressure position and flow is provided between the primary pressure port <NUM> and the secondary pressure port <NUM>; the crossover load sense controller <NUM> is arranged in the combined load sense position and flow is provided between the primary load sense port <NUM> and the secondary load sense port <NUM>; and the load sense bleed controller <NUM> is arranged in the combined bleed position and flow is inhibited between the primary load sense port <NUM> and the common return <NUM> or the sump. In the combined flow mode, the primary pressure port <NUM> and the secondary pressure port <NUM> are coupled (e.g., are equal in pressure), and the primary load sense port <NUM> and the secondary load sense port <NUM> are coupled (e.g., are equal in pressure). The load sense bleed controller <NUM> is blocked so there is a common bleed through the secondary pump <NUM>. The power management controller <NUM> is arranged in the first position so that the secondary load sense system <NUM> of the secondary pump <NUM> controls the destroking of the secondary pump <NUM>. The destroke controller <NUM> is arranged in the isolated position such that the secondary pump <NUM> provides pressurized hydraulic fluid according to the secondary load sense system <NUM>. In some embodiments, the multiple pump hydraulic system <NUM> is used in the combined flow mode when the control system <NUM> senses that one or more of the EHR ports <NUM>-<NUM> through <NUM>-<NUM> or the power beyond port <NUM>-<NUM> is in use.

In the power management combined flow mode, the multiple pump hydraulic system <NUM> is arranged similarly to the combined flow mode. Additionally, the power management spool <NUM> is arranged in the second position so that the first secondary spool <NUM> is isolated and the destroke signal (e.g., the destroke hydraulic pressure) is provided from the first primary spool <NUM> to the second secondary spool <NUM> via the power management spool <NUM>, thereby providing load sense operations for the secondary pump <NUM> that are dictated by the primary load sense system <NUM> of the primary pump <NUM>. The power management spool <NUM> is controlled by the control system <NUM>. When arranged in the power management combined flow mode, the first primary spool <NUM> of the primary load sense system <NUM> controls the stroke of both the primary pump <NUM> and the secondary pump <NUM>. In the first position (e.g., leftmost in <FIG>), the destroke signal (e.g., a destroke hydraulic pressure) is sent to both the primary pump <NUM> and the secondary pump <NUM> so that both pumps are destroked. In the second position (e.g., center in <FIG>) the destroke signal is sent to only the secondary pump <NUM> so that the primary pump <NUM> operates normally with load sense control and the secondary pump <NUM> is destroked. In the third position (e.g., rightmost in <FIG>), the destroke signal is inhibited or isolated to the primary pump <NUM> and the secondary pump <NUM> so that both pumps operate at full stroke.

In the separate flow mode, also called a parallel mode, the primary pump <NUM> and the secondary pump <NUM> operate independently and the primary pump <NUM> may be used to service a first portion of the hydraulic system <NUM> (e.g., the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>) and the secondary pump <NUM> may be used to service a second portion of the hydraulic system <NUM> (e.g., the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>). In some embodiments, the return flow from the primary pump <NUM> and ports associated with the primary pump <NUM> may combine with return flow from the secondary pump <NUM> and ports associated with the secondary pump <NUM>. In the separate flow mode (shown in <FIG>), the crossover pressure controller <NUM> is arranged in the separate pressure position and flow is inhibited between the primary pressure port <NUM> and the secondary pressure port <NUM>; the crossover load sense controller <NUM> is arranged in the separate load sense position and flow is inhibited between the primary load sense port <NUM> and the secondary load sense port <NUM>; the load sense bleed controller <NUM> is arranged in the separate bleed position and flow is provided between the primary load sense port <NUM> and the common return <NUM> or the sump; and the power management spool <NUM> is arranged in the first position (e.g., with the solenoid de-energized) so that load sense functions are provided independently by the primary pump <NUM> and the secondary pump <NUM>. In the separate flow mode, the primary pump <NUM> and the secondary pump <NUM> each regulate and provide the pressure and flow of hydraulic fluid set by the operator, and load sense and load sense bleed operate separately for the primary pump <NUM> and the secondary pump <NUM> with a combined common return <NUM>.

In the destroked separate flow mode, the multiple pump hydraulic system <NUM> is arranged similarly to the separate flow mode. Additionally, power is provided to the solenoid of the destroke controller <NUM> so that the spool of the destroke controller <NUM> is arranged in the destroke position and flow is provided from the pressurized output of the primary pump <NUM> via the primary pressure port <NUM> to the displacement actuator of the secondary variable displacement pump system <NUM> such that the secondary pump <NUM> is destroked. In some embodiments, the control system <NUM> provides power to the solenoid of the destroke controller <NUM> when no load is detected, or nothing is connected to the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and/or the power beyond port <NUM>-<NUM>. In some embodiments, when loads are connected to the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and/or the power beyond port <NUM>-<NUM>, the solenoid of the destroke controller <NUM> is not energized and the separate flow mode is utilized. The destroked separate flow mode can be implemented by the control system <NUM> based on user inputs (e.g., the user selects via the operator interface <NUM> that no loads are connected to EHR ports <NUM>-<NUM> through <NUM>-<NUM> and/or the power beyond port <NUM>-<NUM>) or based on automatic recognition (e.g., the control system <NUM> recognizes via one or more sensors, physical or virtual, that no loads are connected to the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and/or the power beyond port <NUM>-<NUM>).

As shown in <FIG>, which discloses a hydraulic system not part of the present invention, the hydraulic system <NUM> shown in <FIG> can include a multiple pump hydraulic system <NUM> including a primary pump <NUM> and a twin or secondary pump <NUM>. In some embodiments, the primary pump <NUM> is an electrohydraulic control pump that provides a maximum output of eighty-five cubic centimeters per revolution (<NUM> cc/rev). In some embodiments, the secondary pump <NUM> is an electrohydraulic control pump that provides a maximum output of forty-five cubic centimeters per revolution (<NUM> cc/rev).

The primary pump <NUM> and the secondary pump <NUM> can be operated in a combine flow mode and a separate flow mode. In the combined flow mode, also called a serial mode, the primary pump <NUM> and the secondary pump <NUM> work in tandem to provide hydraulic system flow to the EHR system <NUM> and/or the power beyond system <NUM>. In the combined mode, when hydraulic pressure is desired both the primary pump <NUM> and the secondary pump <NUM> operate to provide hydraulic fluid flow and power.

The multiple pump hydraulic system <NUM> provides a user selectable system that operates in the combined flow mode and the separate flow mode. The use of the combined flow mode or the separate flow mode may be desirable based on how the vehicle <NUM> is being used and the ability to switch between the combined flow mode and the separate flow mode improves system efficiencies. The multiple pump hydraulic system <NUM> allows for a user to select a desired operational mode (e.g., from a GUI presented on the operator interface <NUM>, from a selection of switches or buttons, etc.) and automatically arrange the multiple pump hydraulic system <NUM> to provide either the combined flow mode or the separate flow mode. By enabling the operator to have control of the combined flow mode or the separate flow mode on the go it allows the hydraulic system <NUM> to be more robust for the application the vehicle <NUM> is being used in.

The primary pump <NUM> of the multiple pump hydraulic system <NUM> includes a primary variable displacement pump system <NUM> fluidly coupled to a sump and providing pressurized hydraulic fluid to a primary pressure port <NUM>. The displacement of the primary variable displacement pump system <NUM> is controlled by a primary electrohydraulic control system <NUM> in fluid communication with a primary load sensor <NUM>. In some embodiments, the primary electrohydraulic control system <NUM> includes a spool valve that controls operation of a displacement actuator (e.g., a swashplate actuator, etc.). In some embodiments, the primary load sensor <NUM> is an electronic load sense sensor (e.g., a pressure transducer, etc.) fluidly coupled to the primary pressure port <NUM>. A primary pressure determined by the primary load sensor <NUM> is used by the control system <NUM> to control the displacement of the primary variable displacement pump system <NUM> via the primary electrohydraulic control system <NUM> interacting with the displacement actuator. In some embodiments, the primary electrohydraulic control system <NUM> includes center spring returns that center the spool of the primary electrohydraulic control system <NUM> and inhibit flow therethrough. The primary electrohydraulic control system <NUM> includes two solenoids that are selectively energized by the control system <NUM> to shift the spool and stroke or destroke the primary pump <NUM>.

The secondary pump <NUM> of the multiple pump hydraulic system <NUM> includes a secondary variable displacement pump system <NUM> fluidly coupled to a sump (e.g., the same sump used by the primary variable displacement pump system <NUM>) and providing pressurized hydraulic fluid to a secondary pressure port <NUM>. The displacement of the secondary variable displacement pump system <NUM> is controlled by a secondary electrohydraulic control system <NUM> in fluid communication with a secondary load sensor <NUM>. In some embodiments, the secondary electrohydraulic control system <NUM> includes a spool valve that controls operation of a displacement actuator (e.g., a swashplate actuator, etc.). In some embodiments, the secondary load sensor <NUM> is an electronic load sense sensor (e.g., a pressure transducer, etc.) fluidly coupled to the secondary pressure port <NUM>. A secondary pressure determined by the secondary load sensor <NUM> is used by the control system <NUM> to control the displacement of the secondary variable displacement pump system <NUM> via the secondary electrohydraulic control system <NUM> interacting with the displacement actuator. In some embodiments, the secondary electrohydraulic control system <NUM> includes center spring returns that center the spool of the secondary electrohydraulic control system <NUM> and inhibit flow therethrough. The secondary electrohydraulic control system <NUM> includes two solenoids that are selectively energized by the control system <NUM> to shift the spool and stroke or destroke the secondary pump <NUM>.

A primary load <NUM> is coupled to the primary pressure port <NUM> of the primary pump <NUM>. In some embodiments, the primary load <NUM> includes EHR ports <NUM>-<NUM> through <NUM>-<NUM> and power beyond port <NUM>-<NUM>. In some embodiments, the primary load <NUM> includes other loads, or less loads as desired. For example, the primary load <NUM> may include hydraulic base loads of the vehicle <NUM> (e.g., steering brakes, etc.) not related to external implements.

In the separate flow mode (shown in <FIG>), the crossover pressure controller <NUM> is arranged in the separate pressure position and flow is inhibited between the primary pressure port <NUM> and the secondary pressure port <NUM>. In the separate flow mode, the primary pump <NUM> is pressure regulated by the primary electrohydraulic control system <NUM> and the secondary pump <NUM> is pressure regulated by the secondary electrohydraulic control system <NUM>. In the separate flow mode, the multiple pump hydraulic system <NUM> provides the pressure and flow of hydraulic fluid set by the operator, and load sense and load sense bleed separately for the primary pump <NUM> and the secondary pump <NUM> with a combined common return <NUM>.

In the combined flow mode, the crossover pressure controller <NUM> is arranged in the combined pressure position and flow is provided between the primary pressure port <NUM> and the secondary pressure port <NUM>. In the combined flow mode, the primary pressure port <NUM> and the secondary pressure port <NUM> are coupled (e.g., are equal in pressure), and control system <NUM> controls operation of the primary pump <NUM> and the secondary pump <NUM> based on feedback form the primary load sensor <NUM> and the secondary load sensor <NUM>. In some embodiments, the control system <NUM> controls the displacement of the primary pump <NUM> and the secondary pump <NUM> to meet load demands. If the primary pump <NUM> is capable of meeting the load demands, the control system <NUM> destrokes the secondary pump <NUM> via the secondary electrohydraulic control system <NUM> to improve system efficiency thereby reducing fuel consumption of the vehicle <NUM>.

The load demand of the vehicle <NUM> does not always require the output from all pumps of the multiple pump hydraulic system <NUM> depending on the work scenario. The control system <NUM> is structured to electronically sense when the load requires more power and which pumps (e.g., the primary pump <NUM> and/or the secondary pump <NUM>) to load in order to complete the required work.

In operation, the control system <NUM> recognizes when couplers are connected to the EHR system <NUM> and/or the power beyond system <NUM>. Based on the load demand from the base hydraulic functions of the vehicle <NUM>, the EHR system <NUM>, and the power beyond system <NUM>, the multiple pump hydraulic system <NUM> modifies operation to meet the demand. The displacement of the primary pump <NUM> is controlled via the primary electrohydraulic control system <NUM>, and the displacement of the secondary pump <NUM> is controlled via the secondary electrohydraulic control system <NUM> based on signals received from the primary load sensor <NUM> and the secondary load sensor <NUM>.

When the solenoid of the crossover pressure controller <NUM> is energized and the spool is arranged in the combined pressure position, the combined flow mode is engaged, and flow is provided between the primary pressure port <NUM> and the secondary pressure port <NUM>. During combined flow mode operation, the control system <NUM> operates the primary pump <NUM> using on feedback control based on the primary load sensor <NUM> and the secondary load sensor <NUM>. When the load demand can be met by the primary pump <NUM> alone, as determined via the feedback, the control system <NUM> destrokes the secondary pump <NUM> and system efficiency is increased.

When the solenoid of the crossover pressure controller <NUM> is not energized, the spring return biases the spool is arranged in the separate flow position, the separate flow mode is engaged, and flow is inhibited between the primary pressure port <NUM> and the secondary pressure port <NUM>. During separate flow mode operation, the control system <NUM> determines if a load is coupled to the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and/or the power beyond port <NUM>-<NUM>. If no connections are detected, or the operator indicates via the operator interface <NUM> that no loads are connected, then the control system <NUM> commands the secondary electrohydraulic control system <NUM> (e.g., via the solenoids) to destoke the secondary pump <NUM>. If connections are detected, or the operator indicates via the operator interface <NUM> that loads are connected to the EHR ports <NUM>-<NUM> through <NUM>-<NUM> and/or the power beyond port <NUM>-<NUM>, then the control system <NUM> commands the secondary electrohydraulic control system <NUM> (e.g., via the solenoids) to stoke the secondary pump <NUM> and provide pressurized hydraulic fluid. The primary electrohydraulic control system <NUM> controls stroking and destroking of the primary pump <NUM> during separate flow mode operation.

Claim 1:
A multiple pump hydraulic system (<NUM>) for a vehicle (<NUM>), comprising:
a primary hydraulic pump (<NUM>) including a primary displacement actuator and a primary pressure port (<NUM>);
a primary load sense system (<NUM>) fluidly coupled to the primary displacement actuator;
a secondary hydraulic pump (<NUM>) including a secondary displacement actuator and a secondary pressure port (<NUM>);
a secondary load sense system (<NUM>) fluidly coupled to the secondary displacement actuator; and
a crossover pressure controller (<NUM>) coupled between the primary pressure port (<NUM>) and the secondary pressure port (<NUM>) and including:
a selectively energizable crossover pressure solenoid, and
a crossover pressure spool movable by the crossover pressure solenoid between a combined pressure position providing fluid communication between the primary pressure port (<NUM>) and the secondary pressure port (<NUM>), and a separate pressure position inhibiting fluid communication between the primary pressure port (<NUM>) and the secondary pressure port (<NUM>),
wherein the primary hydraulic pump (<NUM>) further includes a primary load sense port (<NUM>), and wherein the secondary hydraulic pump (<NUM>) further includes a secondary load sense port (<NUM>), the multiple pump hydraulic system (<NUM>) further comprising a crossover load sense controller (<NUM>) coupled between the primary load sense port (<NUM>) and the secondary load sense port (<NUM>) and including:
a selectively energizable crossover load sense solenoid, and
a crossover load sense spool movable by the crossover load sense solenoid between:
a combined load sense position providing fluid communication between the primary load sense port (<NUM>) and the secondary load sense port (<NUM>), and
a separate load sense position inhibiting fluid communication between the
primary load sense port (<NUM>) and the secondary load sense port (<NUM>), said system (<NUM>) is characterized in that it further comprises a load sense bleed controller (<NUM>) coupled between the primary load sense port (<NUM>) and a return and including:
a selectively energizable bleed solenoid, and
a bleed spool movable by the bleed solenoid between:
a combined bleed position inhibiting flow between the primary load sense port (<NUM>) and the return, and
a separate bleed position providing flow between the primary load sense port (<NUM>) and the return.