Abstract:
The present disclosure provides a work machine having a frame and a front and rear wheel axle. The machine includes a cab coupled to the frame. The cab is configured to include controls for controlling the operation of the work machine. The machine also includes an electrically-powered drive assembly coupled to the frame and front and rear axles and an inverter electrically coupled to the electrically-powered drive assembly. The machine further includes a platform assembly disposed adjacent the cab and coupled to the frame. The platform assembly comprises an outer wall at least partially surrounding the inverter.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an electric drive loader, and in particular to mounting an inverter to an electric drive loader. 
       BACKGROUND OF THE INVENTION 
       [0002]    Work vehicles such as a loader can be used in construction for loading material into and onto other types of machinery. A conventional loader, e.g., front loader, bucket loader, front end loader, etc., is a type of tractor with a front-mounted bucket connected to the end of two booms for scooping material from the ground. The loader can include front and rear wheels, or in alternative forms, it may include tracks. The loader can also include a hydraulically-actuated pivot point disposed between the front and rear axes to provide articulated steering. Articulated steering can provide enhanced maneuverability for a given wheelbase. 
         [0003]    A conventional loader, such as the John Deere 844K Wheel Loader, can include a conventional fuel-injection engine and transmission with a torque converter. An example of a powertrain and drive assembly for a conventional loader is shown in  FIG. 1 . The powertrain and drive assembly  100  includes a conventional engine  102  and torque converter transmission  104 . The transmission  104  can be a 5-speed transmission with torque converter lockup in different gear ranges for better acceleration, speed cycles, power and fuel efficiency during transport, and ramp climbing. One or more hydraulic pumps  112  can be mounted to the transmission  104  and operated at engine speed. The conventional loader further includes a front axle  106  and a rear axle  108  to which wheels or tracks can be mounted. A driveline  110  is disposed between the transmission  104  and front axle  106  and rear axle  108  for transferring power thereto. 
         [0004]    New technology, however, is being introduced to provide an electric drive loader. As technology pushes toward electric drive, and away from torque converter transmissions, new hardware and additional components are required for the electrification of the loader. As a result, there are challenges in packaging the new hardware and components within the loader without changing or modifying the design of the loader. For example, an inverter is required for an electric drive loader to converter direct current (DC) to alternating current (AC). The layout and space restrictions of the loader, however, make it difficult to find a location for the inverter that provides adequate protection from surrounding elements. 
         [0005]    A need therefore exists to provide a packaging layout of an electric drive loader with an inverter that meets the space requirements of the loader and provides adequate protection to the inverter. In addition, it is desirable to package the inverter in a location that provides easy accessibility thereto for servicing, easy assembly, and a short routing of high voltage cables between the inverter and generator. 
       SUMMARY 
       [0006]    In an exemplary embodiment of the present disclosure, a work machine is provided having a frame and a front and rear wheel axle. The machine includes a cab coupled to the frame such that the cab is configured to include controls for controlling the operation of the work machine. The machine also includes an electrically-powered drive assembly coupled to the frame and front and rear axles and an inverter electrically coupled to the electrically-powered drive assembly. A platform assembly is disposed adjacent the cab and coupled to the frame. The platform assembly comprises an outer wall at least partially surrounding the inverter. 
         [0007]    In one aspect of this embodiment, the outer wall substantially encloses the inverter. In a different aspect, the outer wall comprises a plurality of outer walls that form an outer enclosure such that the outer enclosure defines an interior space into which the inverter is disposed. The outer wall can form a top step adjacent the cab. 
         [0008]    In another aspect of this embodiment, the electrically-powered drive assembly can include an engine; a generator coupled to the engine and adapted to convert mechanical energy from the engine into electrical energy; an electric motor adapted to receive the electrical energy from the generator and convert to mechanical energy; a hybrid transmission coupled to the electric motor and adapted to receive the mechanical energy from the electric motor; and a first driveline coupled between the transmission and front wheel axle and a second driveline coupled between the transmission and rear wheel axle. In addition, a first electric cable can be coupled between the inverter and generator and a second electric cable coupled between the inverter and electric motor. A splitter box can be coupled between the engine and generator. 
         [0009]    Related to this embodiment, a staircase entry can be provided to the cab. The staircase entry can include a plurality of steps and support frame coupled to the frame of the machine. The staircase entry can also be coupled to the platform assembly. In addition, the platform assembly can be disposed on the same side of the machine as an entrance to the cab. In a further aspect of this embodiment, the outer wall of the platform assembly can include a plurality of removably coupled panels. The outer wall can also define a plurality of openings through which electric cables pass for coupling the inverter to the electrically-powered drive assembly. 
         [0010]    In another embodiment, an electric drive loader is provided. The electric drive loader includes a front frame assembly and a rear frame assembly, wherein the front frame assembly and rear frame assembly are adapted to be coupled to one another about an articulation joint. A front axle and a rear axle are also provided such that front ground engaging wheels are coupled to the front axle and rear ground engaging wheels are coupled to the rear axle. A cab is coupled to the front or rear frame and includes an entrance opening on at least one side of the loader. The loader further includes an engine configured to produce mechanical energy, a generator coupled to the engine and configured to convert the mechanical energy from the engine to electrical energy, and an electric motor configured to receive the electrical energy from the generator and convert to mechanical energy. A hybrid transmission is coupled to the electric motor and is adapted to receive the mechanical energy from the electric motor. The loader includes an inverter electrically coupled to the generator and motor and a platform assembly disposed adjacent the entrance opening. The platform assembly is coupled to the frame and comprises an outer wall at least partially surrounding the inverter. 
         [0011]    In one aspect of this embodiment, the outer wall substantially encloses the inverter. In another aspect, the outer wall comprises a plurality of outer walls that form an outer enclosure, the outer enclosure defining an interior space into which the inverter is disposed. In a different aspect, the outer wall forms a top step adjacent the entrance opening of the cab. 
         [0012]    The electric drive loader can include a first electric cable coupled between the inverter and generator and a second electric cable coupled between the inverter and electric motor. The outer wall of the platform assembly can define a plurality of openings through which the first and second electric cables pass for coupling the inverter to the generator and electric motor, respectively. The loader can further include a staircase to the cab, where the staircase entry comprises a plurality of steps and support frame coupled to the platform assembly. In addition, the platform assembly is disposed on the same side of the loader as the entrance opening. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The above-mentioned aspects of the present invention and the manner of obtaining them will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention, taken in conjunction with the accompanying drawings, wherein: 
           [0014]      FIG. 1  is a perspective view of a conventional powertrain and drive assembly of a loader; 
           [0015]      FIG. 2  is a perspective view of an electric drive loader; 
           [0016]      FIG. 3  is a perspective view of one embodiment of a packaging layout of a powertrain and drive assembly of the electric drive loader of  FIG. 2 ; 
           [0017]      FIG. 4  is a perspective view of another embodiment of a packaging layout of a powertrain and drive assembly of the electric drive loader of  FIG. 2 ; 
           [0018]      FIG. 5  is a partial perspective view of a cab entrance and front platform of the loader of  FIG. 2 ; 
           [0019]      FIG. 6  is another partial perspective view of the front platform and inverter mounting location of  FIG. 5 ; and 
           [0020]      FIG. 7  is a schematic front view of the cab entrance and inverter mounting location of  FIG. 5 . 
       
    
    
       [0021]    Corresponding reference numerals are used to indicate corresponding parts throughout the several views. 
       DETAILED DESCRIPTION 
       [0022]    The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention. 
         [0023]    With reference to  FIG. 2  of the present disclosure, a work vehicle such as a front loader  200  is shown. The vehicle  200  includes a front frame  202  and a rear frame assembly  204  that are pivotally joined together at an articulation pivot or joint (not shown). Front ground engaging wheels  206  are coupled to the front frame  202  and rear ground engaging wheels  208  are coupled to the rear frame  204  for supporting and propelling the vehicle  200 . Although the present disclosure illustrates a front loader  200 , it is not limited to such and may include other suitable work vehicles. 
         [0024]    The front frame assembly  102  is provided with a work implement in the form of a loader bucket  214  that is controllably coupled to the front frame assembly  202  by a coupler or mechanical linkage  216 . The bucket  214  can be actuated by a hydraulic cylinder  218  which is coupled to the coupler  216 . In other embodiments, the front frame assembly  102  can be coupled with a pair of forks, a blade, a rotary tiller, a roller level, a rotary cutter, a trencher, and other known work implements. The rear frame assembly  204  can include an operator cab  210  in which an operator controls the vehicle  200  using vehicle controls  212 . The vehicle controls  212  can include a joystick or steering wheel for controlling movement of the front ground engaging wheels  206  and rear ground engaging wheels  208  and articulating the front frame assembly  202  relative to the rear frame assembly  204 . 
         [0025]    The work vehicle  200  can include a cab entrance  220  defined as an opening in the cab  210 . A set of steps and front platform  222  provide easy access to the operator&#39;s cab  210 . A rear platform  224  is also shown in  FIG. 2  mounted to the rear frame  204 . 
         [0026]    Referring to  FIG. 3 , an embodiment is provided illustrating the layout of an electric powertrain and drive assembly  300  of the work vehicle  200 . The assembly  300  includes an engine  302  which is disposed near the rear frame  204  of the vehicle  200 . The engine  300  is designed to operate at an approximately constant speed for improved fuel efficiency and consistent boom and bucket response. The engine  300  is structured to provide power to a generator  308  and hydraulic pump  306 . The generator  308  and hydraulic pump  306  are disposed adjacent to one another in  FIG. 3 , but in an alternative embodiment, the two components can be arranged in axial alignment or otherwise. In  FIG. 3 , a splitter box assembly  304  is coupled between the engine  302  and hydraulic pump  306  and generator  308 . The splitter box  304  is structured to enable the hydraulic pump  306  and generator  308  to be packaged adjacent to one another. 
         [0027]    During operation, the generator  308  can convert mechanical energy from the engine  302  into electrical energy. The generator  308  can produce alternating current (AC). An inverter  310 , which is coupled to the generator  308  via cables  314 , can then convert the alternating current (AC) from the generator  308  into direct current (DC). The direct current can be used for controlling an electric motor  312 , which is also coupled to the inverter  310  via another set of cables  314 . The inverter  310  can converter the direct current (DC) back to alternating current (AC) and supply this to the generator  308 . The electric motor  312  can convert the electrical energy supplied by the generator  308  into mechanical energy to drive an electric drive transmission  316 . The transmission  316  can be a three-speed transmission, for example, that provides speed reduction from the motor  312  to the vehicle&#39;s driveline. In  FIG. 3 , the vehicle includes a front driveline  318  that is coupled between the transmission  316  and front axle  322 . Similarly, the vehicle  200  includes a rear driveline  320  that is coupled between the transmission  316  and rear axle  324 . 
         [0028]    The packaging layout of the components in  FIG. 3  is such that the inverter  310  is coupled on the opposite side of the vehicle  200  from the cab entrance  220 . Here, the inverter  310  can be disposed in a location previously occupied by the vehicle&#39;s battery box (not shown). 
         [0029]    In an alternative embodiment, a different packaging configuration  400  of the components is shown in  FIG. 4 . In this configuration  400 , the inverter  310  is disposed on the same side of the vehicle  200  as the cab entrance  220 . In particular, and as will be further described, the inverter  310  can be disposed in a partially enclosed compartment defined by the front platform  222 . In this location, the routing of the high voltage cables  314  between the inverter  310  and generator  308  and motor  312 , respectively, can be desirably short. Also shown in  FIG. 4  is a brake resistor  402 . The brake resistor  402  can dissipate braking energy not being used for boom and bucket functionality and further reduces brake wear and usage. 
         [0030]    With the conventional torque converter transmission being replaced by an electric hybrid transmission  316 , the packaging and layout of the vehicle included tight spacing requirements for accommodating the inverter  310 . In a non-limiting embodiment, the inverter  310  can have approximate dimensions of 1′×2½′×10″. The inverter  310  can have different dimensions depending on type of vehicle and space requirements. 
         [0031]    Referring to  FIG. 5 , the cab entrance  220  of the vehicle  200  is shown in greater detail. The cab entrance  220  is configured on the left side of the vehicle  200  and includes a defined opening  500  in one side of the operator&#39;s cab  210  to allow entry and exit therefrom. In addition, the cab entrance  220  includes the staircase entry  220  formed by a first step  504 , a second step  506 , and a third step  508 . In other embodiments, the staircase entry  220  can include additional or fewer steps to gain entry to the cab entrance  220 . The staircase entry also includes a frame  510  to provide support to the steps. The front platform  222  is disposed at the top of the staircase entry  220  and adjacent to the defined cab opening  500 . A handle or handrail  502  can be provided for ascending/descending the steps and assisting assistance to and from the cab  210 . 
         [0032]    The front platform  222  can be defined by a top surface  512 , a pair of side surfaces  516 , a front surface  514 , a rear surface  600  ( FIG. 6 ), and a bottom surface  602  ( FIG. 6 ). The top surface  512  can include a plurality of raised dimples to provide better traction when climbing into and out of the cab  210 . In addition, a handle  518  can be coupled to the front surface  514  to assist with traversing the staircase entry  220 . 
         [0033]    With reference to  FIGS. 6 and 7 , the plurality of surfaces of the front platform  222  can define an interior compartment into which the inverter  310  is disposed. The inverter  310  can be at least partially enclosed by the plurality of surfaces to protect the inverter  310  from the surrounding environment. The front platform  222  also allows the inverter  310  to be disposed in a convenient location in the event it needs to be serviced or replaced. It is also conveniently located for assembly purposes. The rear surface  600  can define a plurality of openings through which the cables  314  can pass for coupling to the inverter  310 . 
         [0034]    As shown in  FIG. 6 , the staircase entry frame  510  can include flanges  604 ,  606  for coupling to the side of the vehicle  200 . A lateral frame member  610  can provide further support to the staircase entry frame  510 . Fasteners  608 , such as bolts, screws, etc., can be used to mount the flanges  604 ,  606  to the side of the vehicle  200 . In  FIG. 7 , similar fasteners  700  can be used for coupling the inverter  310  to the bottom surface  602  of the front platform  222 . For example, the inverter  310  can include threaded openings for coupling to the bottom surface  602 . The inverter  310  can also be coupled to one of the two side surfaces  516 , top surface  512 , front surface  514 , or the rear surface  600 . Each of the front surface  514 , rear surface  600 , side surfaces  516 , bottom surface  602  and top surface  512  can be removably coupled panels thereby forming the front platform  222 . In this instance, any one of the panels can be removed to perform service actions on the inverter  310 . In any event, the inverter  310  can be stably coupled to the platform  222  to prevent it from being damaged during vehicle operation. 
         [0035]    While exemplary embodiments incorporating the principles of the present invention have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.