Electrical cabinet

An electric drive work vehicle is provided having a chassis, at least one power distribution system, and a cabinet that houses the at least one power distribution system. The cabinet may be mounted atop the chassis to shield the cabinet and its contents from ground water and debris.

FIELD OF THE DISCLOSURE

The present disclosure relates to work vehicles and, more particularly, to electric drive work vehicles.

BACKGROUND OF THE DISCLOSURE

Electric drive vehicles use one or more electric traction motors for propulsion. In certain embodiments, the electrical power source that powers the traction motors is a hybrid system that includes a combustion engine/electric generator arrangement. In other embodiments, the electrical power source that powers the traction motors includes a battery arrangement or a fuel cell arrangement, for example. On wheeled, electric drive work vehicles, four traction motors may be provided, one at each wheel.

SUMMARY

The present disclosure provides an electric drive work vehicle having a chassis, at least one power distribution system, and a cabinet that houses the at least one power distribution system. The cabinet may be mounted atop the chassis to shield the cabinet and its contents from ground water and debris.

According to an embodiment of the present disclosure, an electric drive work vehicle is provided having a front end and a rear end, a longitudinal axis extending from the front end to the rear end of the work vehicle. The work vehicle includes a chassis, an operator cab supported by the chassis, the operator cab housing an operator of the work vehicle, a platform supported by the chassis, the platform providing access to the operator cab, an engine, at least one traction device positioned to support the chassis on the ground, at least one electric traction motor operatively coupled to the at least one traction device to propel the chassis across the ground, at least one power distribution system that distributes power from the engine to the at least one electric traction motor, and a cabinet that houses the at least one power distribution system, at least a portion of the cabinet being located above the platform and longitudinally forward of the engine.

According to another embodiment of the present disclosure, an electric drive work vehicle is provided having a front end and a rear end, a longitudinal axis extending from the front end to the rear end of the work vehicle. The work vehicle includes a chassis, a work tool moveably coupled to the chassis, at least one hydraulic cylinder configured to move the work tool relative to the chassis, a tank in fluid communication with the at least one hydraulic cylinder to supply hydraulic fluid to the at least one hydraulic cylinder, an operator cab supported by the chassis, the operator cab housing an operator of the work vehicle, a power source, at least one traction device positioned to support the chassis on the ground, at least one electric traction motor operatively coupled to the at least one traction device to propel the chassis across the ground, at least one power distribution system that distributes power from the power source to the at least one electric traction motor, and a cabinet that houses the at least one power distribution system, the cabinet being located above the tank.

According to yet another embodiment of the present disclosure, an electric drive work vehicle is provided having a front end and a rear end, a longitudinal axis extending from the front end to the rear end of the work vehicle. The work vehicle includes a chassis, a work tool moveably coupled to the chassis at the front end of the work vehicle, an operator cab supported by the chassis, the operator cab housing an operator of the work vehicle, a platform supported by the chassis, the platform providing access to the operator cab, a power source, at least one traction device positioned to support the chassis on the ground, at least one electric traction motor operatively coupled to the at least one traction device to propel the chassis across the ground, at least one power distribution system that distributes power from the power source to the at least one electric traction motor, and a cabinet that houses the at least one power distribution system, at least a portion of the cabinet being located above the platform and longitudinally rearward of the work tool.

DETAILED DESCRIPTION

Referring toFIGS. 1-3, an electric drive work vehicle is provided in the form of a loader10. Although the vehicle is illustrated and described herein as loader10, the vehicle may be in the form of a tractor, a bulldozer, a motor grader, an excavator, or another agricultural or utility electric drive vehicle, for example. As shown inFIG. 2, loader10includes longitudinal axis11. Chassis12of loader10includes opposing left and right sides14a,14b, that run substantially parallel to longitudinal axis11from front end16to rear end18. In certain embodiments, loader10is an articulating vehicle, such that front end16of chassis12is able to pivot relative to rear end18of chassis12.

Loader10also includes a plurality of traction devices, illustratively left-side and right-side front wheels20a,20b, and left-side and right-side rear wheels22a,22b, that cooperate to support chassis12above the ground and to propel chassis12across the ground. Although loader10is shown and described herein as a wheeled loader, it is within the scope of the present disclosure that other types of loaders may be used, such as tracked loaders having belts or steel tracks as the traction devices.

At rear end18of loader10, chassis12defines engine housing30for enclosing and protecting engine32, as shown inFIG. 3. Engine housing30may include a pivotable door34to allow the operator to selectively access engine32and other components located inside engine housing30.

Between front end16and rear end18of loader10, chassis12supports operator cab40for housing and protecting the operator of loader10. Operator cab40may include foot pedals, a steering wheel, joysticks, monitors, and other controls (not shown) for operating loader10. The operator is able to access operator cab40by climbing steps42and then walking across platform44, preferably while gripping handle bars46and railings48. In the illustrated embodiment ofFIG. 1, platform44runs along left side14aof chassis12above the left-side rear wheel22aand along right side14bof chassis12above the right-side rear wheel22b.

At front end16of loader10, chassis12supports a work tool in the form of bucket50. Other suitable work tools include, for example, blades, forks, tillers, and mowers. Bucket50is moveably coupled to chassis12via linkage52for picking up or scooping dirt and other materials from the ground and for carrying and dumping such materials. In use, a plurality of hydraulic cylinders54receive pressurized hydraulic fluid from tank56(FIG. 3) to move bucket50relative to linkage52and to move linkage52relative to chassis12. The operator may control hydraulic cylinders54using joysticks or other controls (not shown) located within operator cab40. In the illustrated embodiment ofFIG. 3, tank56is under-mounted to chassis12beneath platform44.

Referring next toFIG. 4, an electric drive system60of loader10is illustrated schematically. The electric drive system60ofFIG. 4is a dual system having two distinct power paths61a,61b, but it is also within the scope of the present disclosure that a single power path may be provided.

The illustrative electric drive system60ofFIG. 4includes engine32, which is illustratively an internal combustion engine. Engine32is coupled to fuel source (not shown) to receive a suitable fuel (e.g., diesel fuel). The output of engine32is mechanically coupled to the input of gearbox64, and the output of gearbox64is mechanically coupled to first and second generators66a,66b, which convert mechanical energy from engine32to electrical energy. Each generator66a,66b, may be configured as a three-phase interior-permanent-magnet (IPM) synchronous generator, for example. Although the electrical power source of electric drive system60is illustrated and described herein as an arrangement of internal combustion engine32and generators66a,66b, it is also within the scope of the present disclosure that the electrical power source may be a battery arrangement, a fuel cell arrangement, or combinations thereof.

The illustrative electric drive system60ofFIG. 4also includes first and second power distribution systems70a,70b. Each generator66a,66b, is coupled to a corresponding power distribution system70a,70b, via first and second power cables68a,68b, respectively. Each power cable68a,68b, may include multiple electrical cables, and each electrical cable may include one or more electrical conductors.

The illustrative electric drive system60ofFIG. 4further includes controller72, which may include appropriate sensors, controllers, microcontrollers, microprocessors, digital signal processors, memory modules, or other electronic components. As shown inFIG. 4, controller72communicates with power distribution systems70a,70b, via communication cables74a,74b, respectively, for sending control signals, such as ground speed signals, steering signals, and braking signals, to power distribution systems70a,70b. Controller72may also provide control functionalities to other components of loader10, such as engine32.

The illustrative electric drive system60ofFIG. 4still further includes a left-side front traction motor80a(which is configured to drive the corresponding left-side front wheel20a), a right-side front traction motor80b(which is configured to drive the corresponding right-side front wheel20b), a left-side rear traction motor82a(which is configured to drive the corresponding left-side rear wheel22a), and a right-side rear traction motor82b(which is configured to drive the corresponding right-side rear wheel22b). Although four traction motors80a,80b,82a,82b, are illustrated and described herein, it is within the scope of the present disclosure that electric drive system60of loader10may have more than four or less than four traction motors, depending on the intended application. Each traction motor80a,80b,82a,82b, may be configured as a three-phase switched reluctance (SR) motor, for example.

Each power distribution system70a,70b, manages the interconnection between generators66a,66b, and traction motors80a,80b,82a,82b. As discussed further below, each power distribution system70a,70b, contains sufficient microprocessor and power semiconductor technology, which may be in the form of distinct power electronics modules, to monitor and/or regulate the attached generators66a,66b, and traction motors80a,80b,82a,82b. For example, based on the control signals received from controller72, the modules of power distribution systems70a,70b, may be configured to selectively supply the necessary electrical power to traction motors80a,80b,82a,82b. Additionally, the modules of power distribution systems70a,70b, may be configured as power inverters to convert the power from generators66a,66b, to a form suitable for use by fraction motors80a,80b,82a,82b.

In the illustrated embodiment ofFIG. 4, power distribution systems70a,70b, operate in a “crosswise” or “quasi-parallel” manner. The first power distribution system70aselectively supplies electrical power to the right-side front traction motor80bvia power cable90band, at the opposite corner of loader10, to the left-side rear traction motor82avia power cable92a. The second power distribution system70bselectively supplies electrical power to the left-side front traction motor80avia power cable90aand, at the opposite corner of loader10, to the right-side rear fraction motor82bvia power cable92b. This “crosswise” arrangement balances power distribution to the left and right sides14a,14b, of loader10. For example, if wheels20a,22a, on the left side14aof loader10lose traction, such as when traveling on a sloping hill, the tractive load on the right side14bof loader10will be distributed between both power distribution systems70a,70b. Each power cable90a,90b,92a,92b, may include one or more electrical conductors. It is also within the scope of the present disclosure that the connections between power distribution systems70a,70b, and fraction motors80a,80b,82a,82b, may vary from the arrangement depicted inFIG. 4.

Referring next toFIG. 5, the first and second power distribution systems70a,70b, are shown and described in more detail. As discussed above, each power distribution system70a,70b, may include a plurality of distinct power electronics modules for managing the interconnection between generators66a,66b, and traction motors80a,80b,82a,82b. In the illustrated embodiment ofFIG. 5, the first power distribution system70aincludes a first module100aassociated with the first generator66a, a second module102aassociated with the right-side front traction motor80b, and a third module104aassociated with the left-side rear traction motor82a. The second power distribution system70bincludes a first module100bassociated with the second generator66b, a second module102bassociated with the left-side front traction motor80a, and a third module104bassociated with the right-side rear traction motor82b.

The first modules100a,100b, of each power distribution system70a,70b, may include power converters in the form of AC-to-DC converters. The first modules100a,100b, may receive three-phase AC power inputs from the respective generators66a,66b, via power cables68a,68b, and may output DC power to a corresponding power bus assembly110a,110b. The first modules100a,100b, may also be configured to control the operation of brake resistors (not shown) to dissipate power from the corresponding power bus assembly110a,110b.

As shown inFIG. 5, each power bus assembly110a,110b, includes a positive power rail112a,112b, and a negative power rail114a,114b. The power bus assemblies110a,110b, may supply power at a nominal voltage of, for example, 700 V, and may be configured in a low inductance configuration, so as to minimize the amount of capacitance required for modules100a,100b,102a,102b,104a,104b, of power distribution systems70a,70b. Capacitors116a,116b, are provided between the positive power rail112a,112b, and the negative power rail114a,114b, of each power bus assembly110a,110b.

The second modules102a,102b, and the third modules104a,104b, of each power distribution system70a,70b, may include power converters in the form of DC-to-AC inverters. The second modules102a,102b, and the third modules104a,104b, may receive DC power from the corresponding power bus assembly110a,110b, and may output three-phase AC power to the corresponding traction motors80a,80b,82a,82b, via power cables90a,90b,92a,92b.

Additional details of power distribution systems70a,70b, including modules100a,100b,102a,102b,104a,104b, of power distribution systems70a,70b, may be disclosed in U.S. Pat. No. 7,808,775 to Cherney et al., entitled “Modular Power Distribution System Having a Sealing Arrangement for Use In a Work Machine,” the disclosure of which is expressly incorporated herein by reference.

Referring next toFIGS. 6-8, a housing or cabinet120is provided to enclose and protect power distribution systems70a,70b. The illustrative cabinet120is metallic and generally rectangular in shape and includes a top panel122, a bottom panel123, a left-side panel124athat faces the left side14aof loader10, a right-side panel124bthat faces the right side14bof loader10, a front panel126that faces front end16of loader10, and a rear panel128that faces rear end18of loader10. Adjacent panels122,123,124a,124b,126,128, may be coupled together integrally, by welding, or using suitable mechanical fasteners129, such as bolts, screws, or latches, to define the protective enclosure around power distribution systems70a,70b. It is within the scope of the present disclosure that one or more panels122,123,124a,124b,126,128, of cabinet120may be at least partially transparent to allow the operator to see power distribution systems70a,70b, contained therein.

As shown inFIGS. 5 and 6, power cables68a,68b, provide inputs to the first modules100a,100b, of power distribution systems70a,70b. To accommodate the incoming power cables68a,68b, the illustrative cabinet120defines a plurality of inlet openings150, as shown inFIG. 7. In the illustrated embodiment ofFIG. 8, inlet openings150are located in the front panel126of cabinet120. The first modules100a,100b, also include suitable connectors152, which may be in the form of robust lug terminals, for connecting to the associated power cables68a,68b.

Also, as shown inFIGS. 5 and 6, power cables90a,90b,92a,92b, provide outputs from the second modules102a,102b, and the third modules104a,104b, of power distribution systems70a,70b. To accommodate the outgoing power cables90a,90b,92a,92b, the illustrative cabinet120defines a plurality of outlet openings154, as shown inFIG. 7. In the illustrated embodiment ofFIG. 8, outlet openings154are located in the bottom panel123of cabinet120. In this manner, power cables90a,90b,92a,92b, extend downward through bottom panel123of cabinet120for connecting to traction motors80a,80b,82a,82b. The second modules102a,102b, and the third modules104a,104b, also include suitable connectors156, which may be in the form of robust lug terminals, for connecting to the associated power cables90a,90b,92a,92b.

To reduce electromagnetic emissions from cabinet120, inlet openings150and/or outlet openings154in cabinet120may be shielded by suitable electromagnetic interference (EMI) shields. For example, EMI-gasketed cover assemblies or plates158may be coupled to cabinet120adjacent to inlet openings150and/or outlet openings154. Cover assemblies158may be manufactured using adhesive-backed EMI gaskets, such as the GORE-SHIELD® adhesive-backed EMI gaskets commercially available from W. L. Gore & Associates, Inc. of Newark, Del. Also, circular EMI seals159, also known as gland seals, may surround power cables68a,68b,90a,90b,92a,92b, at locations adjacent to cabinet120. Suitable EMI shields may also be provided at other locations of cabinet120, such as between adjacent panels122,123,124a,124b,126,128, of cabinet120. When cabinet120is assembled, panels122,123,124a,124b,126,128, the EMI-gasketed cover assemblies158, and the EMI shields159all cooperate to form a Faraday cage to reduce EMI. In addition to reducing EMI, panels122,123,124a,124b,126,128, the EMI-gasketed cover assemblies158, and the EMI shields159also cooperate to block entry of debris and water into cabinet120.

Cabinet120may also define one or more openings160to accommodate various cooling lines. In the illustrated embodiment ofFIG. 8, opening160is centrally located in the bottom panel123of cabinet120. In this manner, an incoming, cold-water supply line (not shown) may be coupled to the downward-facing fluid inlet port162and an outgoing, warm-water discharge line (not shown) may be coupled to the downward-facing fluid outlet port164, with fluid inlet port162and fluid outlet port164being shown inFIG. 12. From fluid inlet port162, cooling water is directed around and between modules100a,100b,102a,102b,104a,104b, via a plurality of fluid conduits166to cool the contents of cabinet120. Fluid conduits166may be configured to vent from their highest elevational points, such as near top panel122of cabinet120. After the water in fluid conduits166is heated, the water eventually exits cabinet120through fluid outlet port164.

Openings154and/or openings160in the bottom panel123of cabinet120may also accommodate various electrical cables170for supplying operational electrical power to modules100a,100b,102a,102b,104a,104b. Electrical cables170may be low-voltage cables that are shielded and grounded. As shown inFIG. 9, each module100a,100b,102a,102b,104a,104b, includes low-voltage electrical connectors172for connecting to electrical cables170.

Referring next toFIGS. 9-11, one or more racks180may be provided within cabinet120for receiving and holding power distribution systems70a,70b. As shown inFIG. 11, the illustrative rack180includes a plurality of openings or slots182, each slot182being sized to slidably receive and hold a corresponding module100a,100b,102a,102b,104a,104b, of power distribution systems70a,70b. Rack180may include suitable clamping mechanisms (not shown) to secure modules100a,100b,102a,102b,104a,104b, in place. Additional details of rack180may be disclosed in the above-incorporated U.S. Pat. No. 7,808,775 to Cherney et al.

Power bus assemblies110a,110b, may be mounted atop rack180, as shown inFIG. 11. With modules100a,100b,102a,102b,104a,104b, installed in rack180, power bus assemblies110a,110b, receive electrical power from the first modules100a,100b, and supply electrical power to the second modules102a,102b, and the third modules104a,104b(see alsoFIG. 5). In certain embodiments, each module100a,100b,102a,102b,104a,104b, includes a three-pronged (i.e., positive, negative, and ground prongs), female electrical connector (not shown) that plugs into a male electrical connector (not shown) of the corresponding power bus assembly110a,110b.

Capacitors116a,116b, may also be mounted atop rack180, as shown inFIG. 11. Capacitors116a,116b, may be spaced apart from each other and from modules100a,100b,102a,102b,104a,104b, for better serviceability. According to an exemplary embodiment of the present disclosure, capacitors116a,116b, are exposed to ambient air by projecting out of cabinet120through the top panel122. The ambient air surrounding loader10provides an efficient and reliable cooling source for capacitors116a,116b, which may extend the life of capacitors116a,116b. A perforated or vented lid190may be provided to protect capacitors116a,116b, from physical damage and to shield capacitors116a,116b, from direct solar rays, while still allowing ambient air to enter lid190and reach capacitors116a,116b.

Returning toFIGS. 1-3, the illustrative cabinet120is mounted atop chassis12of loader10. According to an exemplary embodiment of the present disclosure, a majority of cabinet120extends above platform44of chassis12. In the illustrated embodiment ofFIG. 6, the approximate location of platform44relative to cabinet120is represented by plane P. Locating cabinet120atop chassis12shields cabinet120and its contents from ground water and debris, such as dirt and rocks. Also, locating cabinet120atop chassis12and atop tank56(FIG. 3) shields cabinet120and its contents from any hydraulic fluid that may leak from tank56.

The remaining, lower portion of cabinet120may extend beneath platform44of chassis12. Again, in the illustrated embodiment ofFIG. 6, the approximate location of platform44relative to cabinet120is represented by plane P. In this embodiment, platform44of chassis12may provide additional protection for the base of cabinet120, as well as the components that are entering and exiting the base of cabinet120, such as power cables68a,68b,90a,90b,92a,92b, cooling lines (not shown), and electrical cables170.

In a direction parallel to longitudinal axis11, the illustrative cabinet120is located between engine housing30and operator cab40, as shown inFIG. 2. Also, in a direction perpendicular to longitudinal axis11, the illustrative cabinet120is substantially centered on platform44approximately halfway between the left and right sides14a,14b, of chassis12. This central location of cabinet120may protect cabinet120and its contents in the event that loader10collides with an obstruction or another vehicle, for example. In the illustrated embodiment ofFIGS. 2 and 3, the rear panel128of cabinet120abuts engine housing30. In certain embodiments, cabinet120and engine housing30are substantially the same height.

Cabinet120may be secured to chassis12, engine housing30, and/or platform44. For example, in one embodiment, the side panels124a,124b, of cabinet120include rear-facing brackets134for securing cabinet to engine housing30. Each bracket134defines an aperture136for driving a mechanical fastener (not shown), such as a bolt or a screw, into engine housing30.