Patent Publication Number: US-7900740-B2

Title: Method for adjusting a wheel axis of rotation of a scraper and actuation mechanism therefor

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a method and actuation mechanism for raising and lowering a machine frame, and more particularly to a method and actuation mechanism for adjusting a wheel axis of rotation relative to the frame. 
     BACKGROUND 
     Earthmoving equipment is used to perform a variety of operations, including loading, or capturing, material, such as soil, at one location and dumping, or depositing, the material at another location. For example, such material movement may be employed to adjust elevations at a project site. Scrapers, which typically provide quick load, dump, and maneuver time, may be used to perform such operations, and generally include a machine having a bowl within which the material may be captured, and a cutting edge located adjacent a cut opening of the bowl. Although various scraper configurations are available, scrapers are often pulled by a tractor, such as a wheeled or track type tractor. In addition, scrapers may provide their own traction via a separate engine that applies rim pull, or power, to the wheels of the scraper. In either arrangement, scrapers may also be pushed or pulled by a separate machine, or tractor, to provide additional power for scraper operations. 
     During a typical operation, or duty cycle, the scraper may be pulled forward, at a material capturing location, while the cutting edge of the bowl is pivoted downward to cut through the material. The cutting edge, oriented perpendicular to the direction of travel, may also serve to guide the material into the bowl. When the bowl is loaded to some desired capacity, the cutting edge of the bowl may be pivoted upward so that the cutting edge is out of contact with the material, and the machine may be transported to a location where the soil is to be deposited. After the material is deposited, often with the assistance of an ejector mechanism, the scraper may be returned to the material capturing location, and the duty cycle may be repeated. 
     Often, there is a desire to provide a level cut with the cutting edge of the scraper. However, if the bowl of the scraper is loaded unevenly, a side of the bowl may be weighted more heavily, which may result in an uneven cut. Operating across a path having various topographical changes may cause the left or right set of wheels to operate at an elevated level relative to the other set of wheels, which may also result in an uneven cut. To improve cutting in these situations, the cutting edge may be adjusted toward a parallel position relative to the material. According to one example, as shown in U.S. Pat. No. 5,561,924, one of the wheel hubs, supporting left and right wheels on eccentric spindles, may be rotated slightly to tilt the bowl of the scraper and, thus, cutting edge, to reorient the cutting edge relative to the ground. Specifically, a linear actuator, actuated by a motor, is used to independently adjust a rotation of the wheel hubs, through a horizontal displacement, to tilt the bowl and, thus, cutting edge relative to the ground. Although this arrangement may provide more even cutting, it should be appreciated that there is also a continuing need to improve efficiency of scraper operations by reducing the energy required to fill the bowl to its desired capacity. 
     The present disclosure is directed to one or more of the problems set forth above. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect, a machine includes an axle assembly coupled with a frame and defining a central axis. The axle assembly includes a wheel axle disposed within a spindle housing, and a rotary actuator configured to rotate the wheel axle about the central axis by rotating the spindle housing. 
     In another aspect, a machine includes a frame and an axle assembly coupled with the frame. The axle assembly includes a central axle having a central axle gear at an end thereof. A first wheel axle is disposed within a first spindle housing and includes a first wheel axle gear rotatably coupled with the central axle gear. An actuator is configured to rotate the first wheel axle about the central axle by rotating the first spindle housing. 
     In yet another aspect, a scraper includes a scraper bowl supported on a frame and having a scraper blade disposed at a front portion thereof. An axle assembly, including a central axle, is coupled with the frame and disposed at a rear portion of the scraper bowl. A first wheel axle is rotatably coupled with a first end of the central axle and disposed within a first spindle housing. A second wheel axle is rotatably coupled with a second end of the central axle and disposed within a second spindle housing. A rotary actuator is configured to rotate the first wheel axle and the second wheel axle about the central axle by rotating the first spindle housing and the second spindle housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side diagrammatic view of a machine, according to the present disclosure; 
         FIG. 2  is a perspective view of an axle assembly of the machine of  FIG. 1 ; 
         FIG. 3  is a partially exploded perspective view of a portion of the axle assembly of  FIG. 2 ; 
         FIG. 4  is an alternative perspective view, shown partially exploded, of the axle assembly of  FIG. 2 ; and 
         FIG. 5  is a simplified block diagram of a control system for use with the machine of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment of a machine  10  is shown generally in  FIG. 1 . The machine  10 , as shown, includes a scraper  12  attached to a tractor  14  through an articulated hitch  16 . Although the tractor  14  is depicted as a wheeled tractor, it should be appreciated that scraper  12  may be attached and, thus, pulled or towed by any machine or vehicle, including wheeled or track type tractors. The scraper  12 , which may generally include a frame  18  having an axle assembly  20  about which a scraper bowl  22  may pivot, may also be operated in a variety of configurations, including, for example, a push-pull configuration, as is well known in the art. 
     Scraper bowl  22  may define a cut opening  24 , at a front portion  26  of the scraper bowl  22 , with a cutting edge, such as a scraper blade  28 , positioned adjacent the cut opening  24 . During an exemplary operation, the scraper bowl  22  may be pivoted downward about the axle assembly  20 , such as by using one or more scraper bowl actuators or cylinders  30 , to engage the scraper blade  28  with material  32 , such as, for example, soil. Such material  32  may be collected within the scraper bowl  22  as the tractor  14  and scraper  12  are maneuvered over the material  32 . Although a simplified embodiment is described, it should be appreciated that scraper  12  may include additional components or features, such as, for example, an auger attachment, elevator mechanism, or ejector. 
     The tractor  14  may provide the sole means for propulsion and, in such arrangements, the tractor  14  and scraper  12  may include a single drive axle, such as, for example, a drive axle of a front axle assembly  34 . The front axle assembly  34  may be coupled with a frame  36 , or front frame, of the tractor  14 , which may support a front engine compartment  38 . An engine, such as an internal combustion engine, or other power source may be housed within the front engine compartment  38  and may provide power to front wheels  40  of the front axle assembly  34 . According to some embodiments, the scraper  12  may also include propulsion means, such as an internal combustion engine or other power source disposed within a rear engine compartment  42 , for driving rear wheels  44  of axle assembly  20 , also referenced herein as a rear axle assembly. The rear axle assembly  20 , disposed at a rear portion  46  of the scraper bowl  22 , may thus, according to such tandem powered arrangements, provide its own power, or traction. 
     An operator control station  48  may be supported on the front frame  36 , and may include known devices, such as, for example, a seat assembly  50  and a steering device  52  that facilitate operator control of the tractor  14  and/or scraper  12 . The operator control station  48  may include various other devices, including, but not limited to, one or more machine operation controllers  54 . For example, one or more machine operation controllers  54  may be provided for selecting or controlling an engine speed of an internal combustion engine provided within either or both of engine compartments  38  and  42 . Further, one or more machine operation controllers  54  may be provided for controlling operation of the scraper  12 , such as by controlling movement of the scraper bowl actuators or cylinders  30 . Additional controls and devices, as should be appreciated, may also be provided within the operator control station  48  for controlling various operational aspects of the tractor  14  and/or scraper  12 . Such control, as referenced herein, may include either of mechanical or electronic control means, or a combination thereof. 
     Turning now to  FIG. 2 , portions of the axle assembly  20 , or rear axle assembly, of the scraper  12  are shown. The rear axle assembly  20  may be attached to the frame  18  of the scraper  12  using any known attachment means, and may support wheels, such as the rear wheels  44  shown in  FIG. 1 . The rear axle assembly  20 , according to one embodiment, may generally include a central housing  60  that may be oriented along a first, or central, axis A 1  and may include the attachment means (e.g., fasteners) to frame  18 , referenced above. A first spindle housing  62 , including a first offset channel  64 , may be attached to the central housing  60  at a first end  66  of the central housing  60 . Similarly, a second spindle housing  68 , having a second offset channel  70 , may be attached at a second end  72  of the central housing  60 . First and second offset channels  64  and  70 , defining a wheel axis of rotation, or offset axis, A 2 , according to the exemplary embodiment, may be radially spaced from the central axis A 1 . 
     A first wheel axle  74  and a second wheel axle  76 , which may each be powered by an internal combustion engine, or other power source, of rear engine compartment  42 , may, in turn, be configured to drive wheels, such as wheels  44  of  FIG. 1 . Specifically, as shown, the first wheel axle  74  may be disposed within the first offset channel  64 , while the second wheel axle  76  may be disposed within the second offset channel  70 . According to one embodiment, the set of wheel axles  74  and  76  may be configured to drive wheels  44  ( FIG. 1 ), which may each include a pair of wheels, through a final drive assembly, or final drive planetary gear set, as is known in the art. As such, the wheels, such as wheels  44  of  FIG. 1 , may be rotatably mounted on the first and second spindle housings  62  and  68  or, more specifically, first and second offset channels  64  and  70 . It should be appreciated, however, that, according to some embodiments, wheels  44  may not be directly driven by an engine, or other power source, of scraper  12  and, therefore, some of the drive components described herein may be eliminated 
     Since the second end  72  of central housing  60 , including second spindle housing  68 , may represent a mirror image of the corresponding components described with respect to the first end  66 , only the first end  66  will be described in greater detail. Specifically, as shown in  FIG. 3 , the first spindle housing  62 , at a first end  90  thereof, may be connected to the central housing  60  through a repositioning disk  92 . More specifically, a first side  94  of the repositioning disk  92  may be rotatably received within the central housing  60 , such as by using known wheel or roller bearings, while a second side  96  of the repositioning disk  92  may be fixedly attached, such as through a bolted connection, to the first spindle housing  62 . A central axle  98 , which may be disposed within the central housing  60  and oriented along the central axis A 1 , may be configured to drivingly engage the first wheel axle  74 . According to one embodiment, for example, a wheel axle gear  100  of the first wheel axle  74  and a central axle gear  102  of the central axle  98  may be rotatably coupled, or in mesh, and may be disposed within an opening  104  of the repositioning disk  92 . 
     Turning now to  FIG. 4 , a repositioning drive shaft, such as a first repositioning drive shaft, shown generally at  110 , may include a first driven end  112  and a second driving end  114 . The second driving end  114  may include a repositioning drive gear  116 , which may be rotatably coupled, or in mesh, with an internal gear surface  118  of the repositioning disk  92 . It should be appreciated that the repositioning disk  92 , having a fixed position relative to the first spindle housing  62 , may be integral with the first spindle housing  62 . As a result, the internal gear surface  118  may be provided on a surface, such as an internal surface, of the first spindle housing  62 . The internal gear surface  118  may be continuous about the internal surface of the repositioning disk  92  or may be discontinuous, as shown. According to one embodiment, it may be preferable to provide sufficient gear surface  118  to allow rotation of the repositioning disk  92  and, thus, first spindle housing  62 , through at least 170 degrees. Further, it may be desirable to rotate both the first spindle housing  62  and the second spindle housing  68  through at least about 180 degrees. 
     An exemplary control system for controlling the scraper  12 , and other components, of machine  10  and/or tractor  14  is shown generally at  130  in  FIG. 5 . Specifically, the control system  130  may be an electronic control system including one or more electronic controllers, such as electronic controller  132 , for controlling one or more of the various components or systems of the scraper  12  and/or tractor  14 . The electronic controller  132  may be of standard design and may include a processor  134 , such as, for example, a central processing unit, a memory  136 , and an input/output circuit that facilitates communication internal and external to the electronic controller  132 . The processor  134  may control operation of the electronic controller  134  by executing operating instructions, such as, for example, computer readable program code stored in memory  136 , wherein operations may be initiated internally or externally to the electronic controller  132 . A control scheme may be utilized that monitors outputs of systems or devices, such as, for example, sensors, actuators, or control units, via the input/output circuit to control inputs to various other systems or devices. 
     The memory  136  may comprise temporary storage areas, such as, for example, cache, virtual memory, or random access memory, or permanent storage areas, such as, for example, read-only memory, removable drives, network/internet storage, hard drives, flash memory, memory sticks, or any other known volatile or non-volatile data storage devices. Such devices may be located internally or externally to the electronic controller  132 . One skilled in the art will appreciate that any computer based system or device utilizing similar components for controlling the machine systems or components described herein, is suitable for use with the present disclosure. 
     The electronic controller  132 , and additional electronic controllers of the control system  130 , may communicate via one or more wired and/or wireless communications lines  138 , or other similar input/output circuits. Further, the electronic controller  132  may communicate with one or more sensors, or other devices, associated with the specific machine system(s) controlled by the electronic controller  132 . For example, and referring generally to  FIGS. 1-5 , electronic controller  132  may be configured to identify a desired position, such as a desired vertical position, of the rear portion  46  of the scraper bowl  22 , based on the position of one of the machine operation controllers  54 , and, in response, adjust the wheel axis of rotation A 2  relative to the central axis A 1  using an actuator  140 . 
     The actuator  140 , also referred to herein as a rotary actuator, may include a first electronically controlled rotation mechanism  142  and a second electronically controlled rotation mechanism  144 . The first and second electronically controlled rotation mechanisms  142  and  144 , which may, for example, include electric or hydraulic motors, may be configured to rotate the first repositioning drive shaft  110  and a second repositioning drive shaft  146 , respectively. The second repositioning drive shaft  146 , as should be appreciated, may operate in a manner similar to that of first repositioning drive shaft  110  and, therefore, will not be separately described. Specifically, for example, the first electronically controlled rotation mechanism  142  may be configured to rotate the first driven end  112  of the repositioning drive shaft  110 . As a result of the rotation, the repositioning drive gear  116  of the repositioning drive shaft  110  may drivingly engage the internal gear surface  118  and, thus, rotate the repositioning disk  92  and first spindle housing  62  relative to the central housing  60 . Further, such rotation may cause the first wheel axle  74 , disposed within the first offset channel  64  of first spindle housing  62 , to rotate about the central axis A 1  or, according to the exemplary embodiment, central axle  98 . 
     Accordingly, the electronic controller  132  may adjust, or rotate, the wheel axis of rotation A 2 , defined by offset channels  64  and  70 , relative to the central axis A 1 , through a continuous range of orientations, as provided by the internal gear surface  118 . Further, an alignment feature may be provided to maintain the pair of wheel axles  74  and  76  along the offset axis A 2  during rotation. For example, the electronic controller  132 , in response to actuation of a machine operation controller  54 , may be configured to simultaneously transmit a first actuation signal to the first electronically controlled rotation mechanism  142  and a second actuation signal to the second electronically controlled rotation mechanism  144  to rotate first and second wheel axles  74  and  76  to similar orientations relative to the central axis A 1 . Such adjustment means may allow a greater vertical displacement of the wheel axis of rotation A 2 , as defined by first and second wheels axles  74  and  76 , relative to the central axis A 1  than horizontal displacement. 
     It should be appreciated that the axle assembly  20  and control system  130 , as described herein, may provide a means for adjusting a vertical position of the frame  18 , which supports the rear portion  46  of scraper bowl  22 . Such adjustments may be made electronically and, further, may be made in response to a position of the front portion  26  of the scraper bowl  22  and/or a weight of material  32  within the scraper bowl  22 . For example, it may be desirable to lower the rear portion  46  of the scraper bowl  22 , by adjusting the wheel axis of rotation A 2 , when the front portion  26  and, thus, cutting edge  28  of the scraper bowl  22  has been lowered and at least some material  32  has been collected within the scraper bowl  22 . Once the scraper bowl  22  has reached a desired capacity, and the collected material  32  is being deposited at a desired location, the wheel axis of rotation A 2  may be raised, or returned to a neutral position, using the adjustment means described herein. Additional adjustments, as should be appreciated, may be made, as desired, throughout operation of the scraper  12 . 
     INDUSTRIAL APPLICABILITY 
     The present disclosure finds potential application in any machine, such as a tractor scraper or a towed scraper, which utilizes a bowl, such as a scraper bowl. Further, the disclosure may be specifically applicable to scrapers having a cutting edge of the scraper bowl that may be lowered by pivoting the cutting edge about an axle assembly. Yet further, the present disclosure may be applicable to scrapers requiring improved efficiency, including reduced energy consumption, during operations. Such machines may include, but are not limited to, single engine scrapers, tandem powered scrapers, scrapers operating in a push-pull configuration, and other machines known in the art that utilize a bowl for collecting material. 
     Referring generally to  FIGS. 1-5 , a machine  10 , such as a scraper  12 , may be pulled by a tractor  14  and may generally include a frame  18  and a rear axle assembly  20 , about which a scraper bowl  22  may pivot. The scraper bowl  22  may define a cut opening  24 , at a front portion  26  of the scraper bowl  22 , with a cutting edge, such as a scraper blade  28 , positioned adjacent the cut opening  24 . During an exemplary operation, the scraper bowl  22  may be pivoted downward about the rear axle assembly  20 , such as by using one or more scraper bowl actuators or cylinders  30 , to engage the scraper blade  28  with material  32 , such as, for example, soil. Such material  32  may be collected within the scraper bowl  22  as the tractor  14  and scraper  12  are maneuvered over the material  32 . It should be appreciated that, as the machine  10  is moved over the material  32  and the scraper blade  28  of the scraper bowl  22  is engaged with the material  32 , the scraper bowl  22  will become partially filled with material  32 . The weight of the material  32 , which may be positioned toward the front portion  26  of the angled scraper bowl  22 , may cause an increase in the amount of power and, thus, energy required to maneuver the tractor  14  and scraper  12  over the material  32 . 
     Utilizing the axle assembly  20  and method, as may be implemented by control system  130 , described herein, may reduce energy consumption when machine  10  is at least partially loaded, as described above. Specifically, for example, when a partially loaded state of the scraper bowl  22  is detected, an operator may actuate a machine operation controller  54  to effectively lower a rear portion  46  of the scraper bowl  22  and, thus, reduce an angle of the scraper bowl  22  relative to the ground. Such adjustment, as should be appreciated, may reduce the energy, or power, required to maneuver the partially loaded and, thus, weighted scraper bowl  22  over the material  32 . Additional benefits, including improvements to unloading material  32  from scraper bowl  22  by adjusting the wheel axis of rotation A 2 , may also be recognized. 
     It should be appreciated that the rotary actuator  140 , as described herein, may include any actuator causing movement by rotating or turning on an axis. As such, the rotary actuator  140  described herein does not include a linear actuator for causing rotation, such as rotation of first spindle housing  62  relative to central housing  60 . Specifically, as explained above, rotary actuator  140  includes, for example, first repositioning drive shaft  110  that, when rotated, engages repositioning drive gear  116  with internal gear surface  118  to rotate first spindle housing  62 . Rotating first spindle housing  62 , as should be appreciated, causes rotation of first wheel axle  74  about central axle  98 . Rotating both first wheel axle  74  and second wheel axle  76 , as described herein, effectively adjusts wheel axis of rotation A 2  relative to the frame  18 , thus raising or lowering the rear portion  46  of the scraper bowl  22  relative to the ground. Further, such rotation may be effected while power is transmitted through the central axle  98  to first and second wheel axles  74  and  76 . 
     It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way. Thus, those skilled in the art will appreciate that other aspects of the disclosure can be obtained from a study of the drawings, the disclosure and the appended claims.