BACKGROUND

Technical Field

[0001 ) The invention includes embodiments that relate to a hoist s> stem, a \ ehicle ha\ ing the hoist s\ stem, and one or more associated methods

Discussion of Art

|0002| In a current ofT-hιghwa\ \ ehicle (OHV) application, an engine of the OHV direcllv mechanicalK dm es one or more rn draulic pumps These pumps supph h> draulic pressure for hoist, steeπng, and other applications Because of the direct engine-pump connection, the pumps necessariK run at a speed proportional to engine speed While this prov ides some efficiencies, a draw back to this approach is that engine speed needs to be increased in response to a load demand on these pumps (e g . in the case of a dumper or haul truck when the truck bed is hoisted), and this ma\ be undesirable due to the commensurate fuel consumption, emissions, noise, and the like that accompam increased engine speed Further, the speed of response time ma\ be undesirablv slow due to the engine speed ramp rates Additionalh . the pumps need to run at the high engine speeds e\ en when the demand on the pumps is low

|0003| Therefore, it ma\ be desirable to ha\ e a svstem or v ehicle with properties and charecteπstics that differ from those properties of current!} av ailable sy stems and v ehicles It ma\ be desirable to hav e a method that differs from those methods currenth av ailable

BRIEF DESCRIPTION

|0004| An embodiment relates to a hoist system The hoist s\ stem includes a hoist pump and an electric motor The electric motor is coupled to an energ> source and to the hoist pump During a first mode of operation, the electric motor receiv es electricity from the energy source and thereb> prov ides mechanical power to the hoist pump During a second mode of operation, the electricity from the energy source is used otherwise than for powering the hoist pump

[0005] In another embodiment, the energy source includes an alternator and an engine mechanically coupled to the alternator The engine is operable to dπve the alternator, with the alternator in turn generating the electricity The engine is mechanically decoupled from the hoist pump (e g , the hoist pump is neither directly nor indirectly mechanically driven by an engine) This allows the alternator to electrically power the electric motor during the first mode of operation, for powering the hoist pump, without hoist pump operation being lied to engine speed or \ ice \ersa

100061 In another embodiment, the electric motor is a traction motor or an auxilian motor re\ ersιbl> coupled to the hoist pump During the first mode of operation, the traction motor or au.\iliar> motor receiv es the electricity from the alternator and thereby provides the mechanical power to the hoist pump During the second mode of operation, the traction motor or auxiliary motor is decoupled from the hoist pump, and the traction motor or auxiliary motor receiv es the electricity from the alternator to mechanically dπv e a propulsion system or an auxiliary sy stem, respectn el> . and not the hoist pump

|0007| In another embodiment, the electric motor is a hoist pump motor The system further includes a controller and a traction motor or motor The energy source further includes a power electronics unit, which ma> be electrically connected to an output of the alternator or otherλv ise During the first mode of operation, the controller controls the power electronics unit to prov ide the electricity to the hoist pump motor, and not to the traction motor or auxiliary motor During the second mode of operation, the controller controls the power electronics unit to pro\ ide the electricity to the traction motor or auxiliary motor, and not the hoist pump motor Thus, in the first mode electricity is pro\ ided to the hoist pump motor for driv ing the hoist pump, and in the second mode electricity is prov ided to the traction motor or auxiliary motor to mechanically driv e a propulsion sy stem or an auxiliary sy stem, respectiv ely |0008] Another embodiment relates to a method for operating a stem in a first mode of operation and a second mode of operation In the first mode of operation, electrical power is directed to flow from an energ> source to an electnc motor The eleclπc motor is coupled to the energy source and to a hoist pump The electnc motor is powered with the electrical power, to run the electric motor for providing mechanical power to the hoist pump In the second mode of operation, the s> stem is sw itched to using the electrical power otherwise than for powering the hoist pump If the s\ stem includes a motor and alternator as (at least part of) the energ\ source, it ma> be the case that the engine is neither mechanical!} nor otherw ise operativeh coupled to the hoist pump, the alternator eleclπcalK powers the electric motor duπng the first mode of operation, for powering the hoist pump, w ithout hoist pump operation being tied to engine speed or \ ιce \ersa In an embodiment, the first and second modes of operation are reali/.ed b> switching use of a traction motor or auxiliaiΛ motor between powering the hoist pump (in the first mode) and powering a propulsion s> stem or au\ιlιar> load, respecln eh In another embodiment, the first and second modes of operation are realized b\ sw itching the output of a pow er electronics unit (such as a traction motor drn er) from prov iding pow er to a hoist pump motor and pro\ iding power to a traction motor or auxiliary motor

DESCRIPTION OF FIGURES

|0009| The draw ings illustrate embodiments contemplated for earn ing out the iin entioii Like reference numbers represent the same, or similar, parts w here used

|OOIO| FIGS 1 and 2 are schematic representations of a hoist s\ stem according to an embodiment of the inv ention, in first and second modes of operation, respectiv ely

[001 1 ] FIG 3 is a schematic representation ol a hoist SN Stem, according to another embodiment

|0012| FIGS 4 and 5 are schematic representations of a hoist system, according to another embodiment of the inv ention, in first and second modes of operation, respectiv e!) [OOI3| FIGS 6-1 1 are schematic representations of respective hoist ss stems, according to \arιous embodiments of the ιn\entιon

[OOI4| FIGS 12 and 13 are schematic representations of respective vehicles, according to tw o embodiments of the invention

DETAILED DESCRIPTION

[0015| The invention includes embodiments that relate to a hoist s> stem. a \ ehicle having the hoist system, and one or more associated methods As used herein, " hoist' ^" refers to a dev ice used for lifting or lowering a load The hoist ma\ employ a hydraulic cylinder or other hydraulic device, or a drum around which a cable wraps A hoist pump is a h\ draulic or other pump that is mechanicalK dm en for cam ing out a work function in or of the hoist An example of a hoist pump is a h\ draulic pump that pumps hydraulic fluid into a h> draulic cv Under that is part of a hoist mechanism

|0016| GeneralK , certain embodiments relate to sv stems and methods where a hoist pump is mechanicalK decoupled from an engine (such as an engine in a dumper or haul truck), and the hoist pump, instead of being direclK or indirectly mechanicalK pow ered b\ the engine, is dπven/operated using an electric motor In one embodiment, the electric motor may be a traction motor that is selectiv e!} coupled to and decoupled from the hoist pump, such that in one mode of operation the traction motor prov ides mechanical pow er to the hoist pump and in another mode of operation the traction motor provides mechanical power to a propulsion system ( "Propulsion s\ stem' ^" refers to equipment used to mov e a vehicle or other load, such as a transmission and wheel set For instances herein where a traction motor is descπbed as interacting w ith a propulsion s\ stem, where the traction motor might be conceptualized as part of the propulsion stem, the propulsion sλ stem ma> be understood as reterring to part(s) ol the propulsion s\ stem other than the traction motor ) In another embodiment, electrical power is selectn el> prov ided to a hoist pump motor b\ itself, to a traction motor b\ itself, and/or both together, depending on a mode of operation This ma> involv e sw itching the output of a power electronics unit (such as a traction motor driv er) from prov iding electrical power to the traction motor to providing electncal power to the hoist pump motor Thus, in one aspect, rather than s\ phon off mechanical torque from the engine, the hoist pump is driven using an electπcalK powered motor If electricity for powering the hoist pump is provided an altenator (coupled to the engine), the engine can operate at am set speed sufficient to drive the alternator to supph enough electrical energ) to the electπc motor Hoist speed can be regulated by the amount of electrical current passed through to the electπc motor, ralher than engine speed or e\ en alternator output

|0017| In an embodiment, a hoist sy stem. haMiig a pliiralit} of operating modes, comprises an electric motor coupled to an energy source and coupled (rev ersibh or otherwise) to a hoist pump During one mode of operation, the electπc motor receiv es clcctncit) from the cncrg\ source and prov ides mechanical power to the hoisl pump FIGS 1 and 2 illustrate an example of such a hoist s\ stem I O The hoist s> stem I O includes a first hoist pump 12 and a first electπc motor 14 The first electric motor 14 is coupled to an energx source 16 and to the first hoist pump 12 Duπng a first mode of operation 18 (FIG I ), the first electπc motor 14 recen es electricity 20 from the energx source 16 and therebv provides mechanical power 22 to the first hoist pump 12 Duπng a second mode of operation 24 (FlG 2). the electricity from the energy source is used otherwise than for powering the first hoist pump 12 ("Used otherwise ^" includes used for another purpose, stored, dissipated, or not used at all Examples include poweπng the electπc motor but where the electric motor is used for some other purpose other than dπung the hoist pump, and routing the electricitv to a dev ice other than the electπc motor ) The s> stem 10 ma> be outfitted w ith a controller and/or power electronics unit as discussed herein

|0018] In another embodiment, with reference to FIG 3. the energ> source 16 of a hoist s> stem 30 includes an alternator 26 and an engine 28 mechanicalh coupled to the alternator 26 The engine 28 is operable to driv e the alternator 26, w ith the alternator 26 in turn generating the eleclπcih 20 The engine 28 is neither directK nor indirectly mechanically coupled to the first hoist pump 12 (The hoist pump 12 is not mechanicalK driv en b> an engine ) This allows the alternator 26 to electricaJlv power the first electπc motor 14 duπng the first mode of operation, for poweπng the first hoist pump 12. w ithout hoist pump operation being lied to engine speed or vice \ ersa The system 30 ma\ be outfitted with a controller and/or power electronics unit as discussed herein

|0019| In another embodiment of a hoist s> stem 40, with reference to FIGS 4 and 5. the first electric motor 14 is a traction motor 32 or an auxiliary motor 34 reversibly coupled to the first hoist pump 12 During a first mode of operation 42 (FIG 4). the traction motor 32 or auxiliary motor 34 receiv es the electπcih 20 from the alternator 26 and prov ides the mechanical power 22 to the first hoist pump 12 During a second mode of operation 44 (FIG 5). the traction motor 32 or au\ιliar> motor 34 is decoupled from the first hoist pump 12, and the traction motor 32 or au\ιlιar\ motor 34 receiv es the eleclricitv 20 from the alternator 26 to mechanicalK drive a propulsion sv slcm 36 or an auxihar. s> stcm 38, respective!) , and not the first hoist pump 12

[0020| The system 40 may further comprise a controller 46 (e g . microcontroller, computer, or other electronics control unit) If so. in an embodiment, the controller 42 is operable to direct the traction motor or auxilian motor to couple to the first hoist pump 12 in the first mode of operation 42, and to the propulsion s\ slem or auxiliary s> stem in the second mode of operation 44 The controller 46 is operable to regulate the electricitv from the alternator to the traction motor or au\ιliarv motor, and thereb\ to control a speed of the first hoist pump, in the first mode of operation ( 'Regulate' ^" means to control the eleclricitv prov ided to the motor, such as stopping or starting the flow of electricity . and/or controlling the amount and characteristics of the electricitv prov ided ) In one mode of operation of the controller 46. the controller modifies the speed of the first hoist pump 12 without modify ing speed or other operation of the engine 28

|0021 | In another embodiment of a hoist sy stem 48, w ith reference to FIG 6. the energv source 16 further comprises a power electronics unit 50 electncallv connected between an output of the alternator 26 and an input of the traction motor 32 or auxilian motor 34 The controller 46 is operablv connected to the power electronics unit 50 for controlling the power electronics unit 50 to regulate the eleclricitv provided from the alternator to the traction motor or au\ilιan motor The power electronics unit 50 ma> include one or more of a motor driv er (circuitrv such as a variable speed inv erter drn e. for taking a power input and outputting signals configured to dπ\ e a motor), inverters, power transistors and other power elements, circuit protection equipment, and switching elements

10022) In another embodiment of a hoist sv stem 52, w ith reference to FIG 7, the sv stem 52 is mounted in a vehicle 54, and the first electric motor 14 (motor for dm ing a hoist pump) is a first traction motor 32 The sv stem 52 further comprises a second traction motor 56 (second electπc motor) that is coupled to a wheel 58 of the v ehicle 54 (the wheel part of a propulsion s\ stem 36 of the v ehicle) such that when the first traction motor 32 is prov iding the mechanical power 22 to the first hoist pump 12. the second traction motor 56 is propelling the wheel 58 to mo\ c the vehicle 54 The SN stem 52 ma> be outfitted w ith a controller and/or pow er electronics unit as discussed herein

|0023| In another embodiment of a hoist sy stem 60. with reference to FIG 8, the first electπc motor 14 is a hoist pump motor 62 The system 60 further includes a controller 46, a traction motor 32 or auxiliary motor 34 (second electπc motor), and a power electronics unit 50. which ma> be electπcalh connected to an output of the alternator 26 or otherwise During a first mode of operation 64, the controller 46 controls the power electronics unit 50 to prov ide the electncιl\ to the hoist pump motor 62. and not to the traction motor 32 or au\ιlιan motor 34 During a second mode of operation 66, the controller 46 controls the power electronics unit 50 to pro\ ide the electπcih to the traction motor 32 or au\ilιar> motor 34, and not the hoist pump motor 62 Thus, in the first mode 64, electπcitv is prov ided to the hoist pump motor for driv ing the hoist pump 12, and in the second mode 66. electπcilv is prov ided to the traction motor or auxiliary motor to mechanicallv driv e a propulsion sv stem 36 or an auxiliary system 38. respectiv elv In addition to the first and second modes, there may be a third mode of operation In the third mode of operation, the controller would control the power electronics unit to provide the electricitv to both the hoist pump motor and to the traction motor or auxiliary motor, for the hoist pump motor to prov ide the mechanical power to the first hoist pump and for the traction molor or auxiliary motor Io concurrent!) mechanicalK drive the propulsion s> stem or the slerrt respectiv e!)

|0024| According to another aspect of the inv ention, a hoisl system ( 10. 30. 40, 48. 52, 60, 74, or otherwise) ma\ include a second hoist pump that is mechanically coupled Io the motor, directlv or indirect!) As an example, w ith reference to FIG 9. a hoist sv stem 68 includes a second hoisl pump 70 that is mechanicalK coupled to the engine 28 The second hoist pump 70 may be mechanicalK directK coupled to the engine 28. or indirectly mechanically coupled to the engine 28. such as through a steering pump 72 that is itself mechanically coupled to the engine In an embodiment, the second hoist pump is relativ e!) smaller in capacit) than the first hoist pump The second hoist pump remains coupled to the engine (directly or \ ιa a steering pump) to receiv e mechanical torque from the engine, and when needed the first hoist pump is emplo\ ed to prov ide hv drauhc lift to the hoist mechanism in coniuction w ith the second hoist pump The first host pump thereby acts as a hoist pump booster In another aspect, the smaller. mechanicalK coupled, second hoist pump ma\ circulate cooling fluid (such as oil) to the brakes in a wet brake sy stem This allows for cooling of the brakes to be performed while the v ehicle is mov ing And a high lev el of coolant flow mav be achiev ed ev en w ith a relativ e!) lower engine speed

|0025| According to another aspect of the inv ention, a hoist sv stem ( 10, 30, 40. 48, 52. 60. 68. or otherwise) ma\ include an energy storage dev ice (e g . comprising or part of the energ> source) that is electrical!} coupled to the first electric motor (the motor used to driv e the hoist pump, e g , a hoist pump motor, or a traction motor or auxiliarv motor) The energy storage dev ice prov ides the electπcih to the first electric motor at least duπng part of a time when the engine 28 is not operating and the alternator 26 is thereby not supplying the electπcih The energ) storage device allows the motor to driv e the hoist pump ev en if the engine is not operating and the alternator is not suppK ing electricitv to the motor As an example, with reference to FIG 10. a hoist svstem 74 comprises an energ) storage dev ice 76 that is electrical!) coupled to a power electronics unit 50 A controller 46 is configured to control the energ-s storage device 76 and/or the power electronics unit 50 for the energy storage device 76 to selectiv ely prov ide electπcih to the power electronics unit 50 (e g . for powering a molor that runs a hoist pump)

(0026] According to another aspect of the inv ention, for hoist systems prov ided w ith an energv storage device, the hoist sv stem ( 10. 30. 40. 48, 52. 60. 68 74 or otherwise) ma\ be mounted in a vehicle hav ing a regenerative braking sv stem The energy storage device is coupled to the regenerativ e braking sv stem. from which the energy storage dev ice can be charged duπng a braking event As an example, with reference to FIG 1 1. a hoist system 78 is mounted in a v ehicle 54 The vehicle has a regenerativ e braking sv stem 80 An energy storage dev ice 76 is coupled to the regenerativ e braking sv stem 80, from which the energy storage device 76 can be charged duπng a braking ev ent of the v ehicle (For example, the sv slem ma\ be configured such thai when the v ehicle is braked, a load of the propulsion sv slcm is placed on a traction motor, with the traction motor being mov ed b\ the propulsion s> stem and therebv generating electπcitv )

|0027| As noted, embodiments of the inv ention may be implemented in or as a v ehicle FIG 12 illustrates another example Here, a v ehicle 82 includes a chassis 84. an energ\ source 16 disposed in the chassis 84, a controller 46 disposed in the chassis 84. a hoist pump motor 62 and a hoist pump 12 disposed in the chassis 84, and a traction motor 32 and a propulsion sv stem 36 disposed in the chassis 84 The energ> source 16 includes an engine 28. an alternator 26 coupled to the engine 28, and a power electronics unit 50 The controller 46 is operablv coupled to the energv source 16 The hoist pump motor 62 is mechanicalh coupled to the hoist pump 12 and electricallv coupled to the power electronics unit 50 The engine 28 is neither mechanically nor otherwise operativ e!) coupled to lhe hoist pump 12 The traction motor 32 is mechanically coupled to the propulsion system 36 and electrical l> coupled to the power electronics unit 50 In a first mode of operation 86, the controller 46 controls the power electronics unit 50 for the power electronics unit 50 to provide electrical power to the hoist pump motor 62 When powered in this manner, the hoist pump molor 62 provides mechanical power to the hoist pump 12 The speed of the hoist activ Uv is controlled bv wav of the controller 46 regulating the flow of electrical power from the power electronics unit to the hoist pump motor In a second mode of operation 88, the controller 46 controls the power electronics unit 50 for the power electronics unit 50 to prov ide electrical power to the traction motor 32 and not the hoist pump motor When powered in this manner, the traction motor 32 prov ides mechanical power to the propulsion s> stem 36 for mov ing the v ehicle 82 The vehicle 82 may include a steering pump 72 (mechanicalh coupled to the engine) and a second hoist pump 70 directh or indirectly mechanicalh coupled to the engine

|0028| In another embodiment of a v ehicle, the v ehicle comprises a chassis, an energv source disposed in the chassis and compπsing an engine and an alternator coupled to the engine, a hoist pump disposed in the chassis, wherein the engine is neither mechanicalh nor otherw ise operalively coupled to the hoist pump, a controller disposed in the chassis and operabh coupled to the energx source, and a traction motor or an auxiliary motor controllable between first and second modes of operation In the first mode of operation, the traction motor or the auxiliary motor is coupled w ith the hoist pump, and in the second mode of operation the traction motor or the auxiliarv motor is coupled w ith a propulsion sv stem of the v ehicle or an aαxilian SN stem of the v ehicle. respectiv e!} The controller is operable to selectiv eh control the traction motor or auxihan motor to the first mode of operation and to the second mode of operation, and to control the energ\ source for supph ing electrical power to the traction motor or auxiliarv motor Thus, during the first mode of operation, the traction motor or auxiliary motor receiv es electrical power from the energΛ source and mechanicalh driv es the hoist pump The controller controls the flow of the electrical power, and thereby controls the speed of the hoist activ ilv Duπng the second mode of operation, the traction motor or auxiliary motor is decoupled from the hoist pump, the traction motor or auxiliary motor receiv es the electrical power from the energ> source and mechanicalh driv es the propulsion s> stem or au\ιliarv s> slem, respectiv e!) , and not the hoist pump An example of such a v ehicle 90 is shown in FlG 13, with the first and second modes of operation being illustrated 92 and 94. respectiveh

[0029| Another embodiment relates to a method for operating a hoist system The hoist sx stem is operated in first and second modes of operation The method comprises, in the first mode of operation, directing electrical power to flow from an energ\ source to a first electric motor The first electπc motor is coupled to the energy source and to a first hoist pump The method further compπses, in the first mode of operation, powering the first electπc motor with the electrical power, in order for the first electπc motor to provide mechanical power to the first hoist pump In the second mode of operation, the system is switched from (i) the first electπc motor providing the mechanical power to the first hoist pump to (it) using the electπcal power otherwise than for powering the first hoist pump

(0030) Another embodiment of the method includes additional or altematn e steps for when the first electπc motor is a traction motor Here, the method further comprises, in the first mode of operation, directing the traction motor to mechanically decouple from a propulsion device and to couple to the first hoist pump In the second mode of operation, the traction motor is directed to mcchanicalh decouple from the first hoist pump and to couple to the propulsion de\ ice

|0031 | Another embodiment of the method includes additional or alternate e steps for when the energy source includes an engine and an alternator, the engine dm ing the alternator for generating the electπcal power Here, the method further compπses, in the first mode of operation, the first electπc motor modify ing a speed of the first hoist pump w ithout modιf\ ιng speed or other operation of the engine The first hoist pump is neither directh nor indirect!) mechanical!} coupled to the engine

(0032] Another embodiment of the method includes additional or allemaln e steps for w hen the first electric motor is a hoist pump motor Here, the method further compπses. in the second mode of operation, using the electπcal power to run a second electπc motor and not the hoist pump motor The second electric motor is a traction motor or an au\ιlιar\ motor

[0033| According to one aspect, a hoist activih is controlled b\ regulating the supply of electπcal power to an electric motor that dπves a hoist pump, where the hoist pump is mechanical K decoupled from an engine (In particular, the hoist pump is not mechanical!} driven, directh or indirect!} , b> an engine ) The hoist actι\ ιt\ ma\ be modified without modif} ing engine speed or operation If the hoist acln ιt\ is hoisting speed, engine speed is unmodified when the hoisting speed is modified For a dumper or haul truck, for example, dumping a load ma> be controlled in response to the hoist actiMtN

|0034| Electπcit} to power a motor for driving a hoist pump ma\ be supplied b\ a power electronics unit. e g . a traction dm er (variable speed inx erter drive) or an auxiliary driver The power electronics unit ma> be connected to the alternator/rectifier Duπng operation, when a hoist pump is required for use. a traction dπ\ er may be disconnected from a traction motor, or an auxiliary dm er ma> be operational disconnected from an auxilian motor (e g . radiator fan motor, traction motor blower, alternator blower, or the like) Once operationally disconnected from us first operational mode, the driv er (power electronics unit) ma> then be used to drive a motor for a hoist pump

(0035) Functionally, the engine speed can be decoupled from the hoist pump speed Additionally, for systems w ith an energ\ storage device, the motor for dm ing the hoist pump can be run from the eleclπcit) stored in an energy storage device The engine speed can be chosen to prov ide optimal fuel efficiency depending on the required load The pump motor can be powered by energ> sources other than the engine torque The hoist pump can be powered by a motor, for example a traction motor, that is itself powered b> an energ} source other than the alternator - for example, an energy storage deuce A suitable energ> storage dev ice includes, for example, a sodium metal halide batten , sodium sulfur, lithium ion batter. , nickel metal h> dπde. nickel cadmium, and the like, as well as other energ> storage mediums (capacitors, fuel cells. fl> wheel devices, and the like) While the energy storage dev ices listed here are not entireh interchangeable, ma\ be selected based on the end use requirements and constraints

10036] In one embodiment, multiple pumps and sources oplimi/e the sv stem usage Such optimi/ation may alTect one or more aspects such as but not limited to. fuel consumption, engine emissions, hoisting time, and noise lev el |0037| Am of the embodiments set forth herein mav be disposed in or implemented as or as part of an off-highway \ ehιcle (OHV) Examples of off- highway \ ehιcles include mining and construction equipment, dumpers and haul trucks, and the like Embodiments are particular!) applicable to large-si/ed haul trucks, e g . 100-400 ton capacity, which require robust hoist s> stems and ma> benefit from enhanced flexbilitx and performance of the hoist s\ slem

|0038| In am of the embodiments set forth herein im olung plural motors, each motor ma\ be provided w ith its ow n motor drn er circuit/unit Thus, for example, although FIGS 8- 12 suggest switching the output of a power electronics unit between plural motors, it could instead be the case that each motor has an indmdual driver, which are controlled by a controller (e g , selectι\ le\ activating or deactivating the drivers) for cam ing out the control functionalilj dcscπbcd herein

[0039| During a first mode of operation 42 (FIG 4), the traction motor 32 or auxilian, motor 34 recen es the electricih 20 from the alternator 26 and provides the mechanical power 22 to the first hoist pump 12 During a second mode of operation 44 (FIG 5) the traction motor 32 or auxilian motor 34 is decoupled from the first hoist pump 12, and the traction motor 32 or aαxilian motor 34 receives the electπcih 20 from the alternator 26 to mechanically drt\ e a propulsion system 36 or an au\ihar\ s\ stem 38. respective!) , and not the first hoist pump 12

|0040| As noted abo\ e. in certain embodiments (e g . FIGS 4-5). a traction molor or auxilian motor mechanically powers a hoist pump (in one mode), and is decoupled from the hoist pump for mechanicalK driving a propulsion sy stem or auxilian svstem (in another mode) A traction molor or auxiliary motor ma\ be selectiv e!) mechanicalK coupled and decoupled between a hoist pump and a propulsion s\ stem or auxiliary ss stem using a controllable s\ stem that includes a transmission and/or clutch mechanism

|004l | Il is to be understood lhal lhe above description is intended Io be illustratn e, and not restπctπe For example, the above-descπbed embodiments (and/or aspects thereof) ma> be used in combination with each other In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosed subiecl matter w ithout departing from its scope While the dimensions and types of mateπals described herein are intended to define the parameters of the disclosed subject matter, the> are by no means limiting and are e\emplar\ embodiments The scope of the described subject matter should, therefore, be determined with reference to the appended claims, along w ith the full scope of equiv alents to which such claims are entitled In the appended claims, the terms "including ^" and "in which ^" are used as the plain-language equivalents of the respective terms "comprising ^" and "wherein " Moreover, in the follow ing claims, the terms "first. ^" "second. ^" and "third." etc are used mereh as labels, and are not intended Io impose numerical requirements on their objects

[0042] The embodiments described herein arc examples of sv stcms and methods hav ing elements corresponding to the elements of the inv ention recited in the claims This wπtten description may enable those of ordinan skill in the art to make and use embodiments hav ing alternativ e elements that likew ise correspond to the elements of the inv ention recited in the claims The scope of the invention thus includes articles. s> stems and methods that do not differ from the literal language of the claims, and further includes other articles. s> stems and methods w ith insubstantial differences from the literal language of the claims While onl\ certain features and embodiments have been illustrated and described herein. manv modifications and changes ma\ occur to one of ordinars skill in the relev ant art The appended claims cover all such modifications and changes