Patent Application
20100122477
The present disclosure relates generally to a hydraulic actuator assembly, and more particularly to a hydraulic actuator assembly for translating linear motion into rotary motion. Such a hydraulic actuator assembly may be used to raise and lower an apron of a scraper, as described herein.
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 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, an apron of the scraper may be pivoted upward, to a raised position, to open, or unblock, the cut opening of the bowl, and also to increase the capacity of the bowl. 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. In addition, the apron may be pivoted downward, to a lowered position, to prevent loss of the material during transport. 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.
To move the apron between raised and lowered positions, mechanisms for actuating mechanical linkages attached to the apron are often employed. According to one example, as shown in U.S. Pat. No. 3,016,633, an apron sector gear is fixed to the front center portion of the apron and follows the vertical section contour of the apron. The apron sector gear is driven by an electric motor through a suitable gear reduction. The electric motor and the gear reductions are fixed to the upper forward bowl structure and move the apron between open and closed positions. Although this arrangement may provide suitable actuation of the apron, it should be appreciated that there is a continuing need for actuation mechanisms that provide smooth operation, increased position resolution, and that satisfy strict spatial requirements.
The present disclosure is directed to one or more of the problems set forth above.
In one aspect, an apron assembly includes an apron having an apron body extending between a first apron side and a second apron side. A portion of the apron includes an arcuate gear surface. A hydraulic actuator assembly includes a linear hydraulic actuator configured to actuate a drive gear, which is in mesh with the arcuate gear surface.
In another aspect, a scraper includes a scraper bowl supported on a frame of the scraper. The scraper bowl includes a first bowl side and a second bowl side. An apron includes an apron body extending between a first apron side and a second apron side. The first apron side is pivotably attached to the first bowl side, and the second apron side is pivotably attached to the second bowl side. A portion of the apron includes an arcuate gear surface. A hydraulic actuator assembly includes a linear hydraulic actuator configured to actuate a drive gear, which is in mesh with the arcuate gear surface.
In yet another aspect, a hydraulic actuator assembly includes a linear hydraulic actuator having a cylinder end and a rod end. A drive block is coupled with the rod end and is mounted on a drive shaft. The drive block includes at least one inwardly extending projection positioned within a helical groove of the drive shaft. At least one drive gear is supported on the drive shaft.
An exemplary embodiment of a machine 10 is shown generally in
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, an apron 30 may be pivoted upward, to a raised position, to open, or unblock, the cut opening 24, and also to increase the capacity of the scraper bowl 22. 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 32, to engage the scraper blade 28 with material 34, such as, for example, soil. Such material 34 may be collected within the scraper bowl 22 as the tractor 14 and scraper 12 are maneuvered over the material 34. When the scraper bowl 22 is loaded to some desired capacity, the scraper blade 28 may be pivoted upward so that the cutting edge is out of contact with the material 34, and the machine 10 may be transported to a location where the material 34 is to be deposited. In addition, the apron 30 may be pivoted downward, to a lowered position, to close, or block, the cut opening 24 to prevent loss of the material 34 during transport. 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 36. The front axle assembly 36 may be coupled with a frame 38, or front frame, of the tractor 14, which may support a front engine compartment 40. An engine, such as an internal combustion engine, or other power source may be housed within the front engine compartment 40 and may provide power to front wheels 40 of the front axle assembly 36. 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 44, for driving rear wheels 46 of axle assembly 20, also referenced herein as a rear axle assembly. The rear axle assembly 20, disposed at a rear portion 48 of the scraper bowl 22, may thus, according to such tandem powered arrangements, provide its own power, or traction.
Either or both of the engines, such as internal combustion engines, of the front engine compartment 40 and the rear engine compartment 44 may provide power to a hydraulic system of the scraper 12. Specifically, an internal combustion engine of the machine 10 may power a hydraulic pump, which may provide a flow of hydraulic fluid to control one or more hydraulic devices of the machine 10. For example, such a hydraulic pump may supply a flow of high-pressure hydraulic fluid to one or more hydraulic actuators, such as scraper bowl cylinders 32, to the control movement of the scraper bowl 22. Hydraulic systems are known and only peripherally within the scope of the present disclosure. Therefore, such hydraulic control will not be discussed herein in greater detail.
An operator control station 50 may be supported on the front frame 38, and may include known devices, such as, for example, a seat assembly 52 and a steering device 54 that facilitate operator control of the tractor 14 and/or scraper 12. The operator control station 50 may include various other devices, including, but not limited to, one or more machine operation controllers 56. For example, one or more machine operation controllers 56 may be provided for selecting or controlling an engine speed of an internal combustion engine provided within either or both of engine compartments 40 and 44. Further, one or more machine operation controllers 56 may be provided for controlling operation of the scraper 12, such as by controlling movement of the scraper bowl actuators or cylinders 32. Additional controls and devices, as should be appreciated, may also be provided within the operator control station 50 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
As shown, a portion of the apron 30 may include a gear surface, such as an arcuate gear surface matching the contour of the apron body 64. Specifically, according to the exemplary embodiment, a first vertically aligned arcuate gear surface 76 and a second vertically aligned arcuate gear surface 78 may be positioned on an external side 80 of the apron 30. The first vertically aligned arcuate gear surface 76 may be positioned at, or near, the first apron side 66, while the second vertically aligned arcuate gear surface 78 may be positioned at, or near, the second apron side 68. Although specific embodiments are shown, it should be appreciated that one or more arcuate gear surfaces may be provided on any portion of the apron 30, such that a drive gear of the hydraulic actuator assembly 62 is positioned to engage the one or more arcuate gear surfaces of the apron 30. The hydraulic actuator assembly 62, according to the exemplary embodiment, may be supported on a support brace 82, which may be perpendicular to and extend between the first bowl side 70 and the second bowl side 72.
The hydraulic actuator assembly 62 may generally include a linear hydraulic actuator 84 configured to actuate one or more drive gears, which are in mesh with the first vertically aligned arcuate gear surface 76 and the second vertically aligned arcuate gear surface 78. For example, the linear hydraulic actuator 84 may be configured to rotate a drive shaft 86. The drive shaft 86, according to one embodiment, may support a first drive gear 88, which is rotatably coupled, or in mesh, with the first vertically aligned arcuate gear surface 76, and a second drive gear 90, which is rotatably coupled, or in mesh, with the second vertically aligned arcuate gear surface 78. Although rotary motion is described, it should be appreciated that the linear hydraulic actuator 84 may be configured to move a flat drive surface, such as a rack, in a linear direction to engage first and second vertically aligned arcuate gear surfaces 76 and 78. Such a drive surface, as should be appreciated, may also have a relatively vertical orientation.
The linear hydraulic actuator 84, which may be actuated using the hydraulic system described above, may be substantially parallel with the drive shaft 86, as shown, and may include a cylinder end 92 and a rod end 94. The rod end 94 may be rotatably coupled with a drive block 96 mounted on the drive shaft 86. The drive block 96, which, according to the exemplary embodiment, may be positioned along the drive shaft 86 between the first drive gear 88 and the second drive gear 90, may be configured to translate linear motion of the linear hydraulic actuator 84 into rotary motion of the drive shaft 86. As shown, the linear hydraulic actuator 84 and the drive shaft 86 may be substantially perpendicular to parallel planes defined by the first apron side 66 and the second apron side 68. Although specific orientations are described, it should be appreciated that the components of the hydraulic actuator assembly 62 may be positioned according to alternative arrangements and still provide the benefits described herein.
The hydraulic actuator assembly 62 may be configured to raise the apron 30 to a raised, or open, position, as shown in
As shown in both
Although two drive gears 88 and 90 and two gear surfaces 76 and 78 are shown, it should be appreciated that any number and/or type of drive gear surface, driven by the linear hydraulic actuator 84, may be configured to drive any number and/or type of gear surfaces of the apron 30. For example, as shown in
Turning now to
It should be appreciated that the apron 30 and hydraulic actuator assembly 62, as described herein, may provide a means for adjusting a position of the apron 30 relative to the 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 34 within the scraper bowl 22. For example, it may be desirable to raise the apron 30 when the front portion 26 and, thus, scraper blade 28 is pivoted downward to engage the material 34. It may also be desirable to lower the apron 30 when the front portion 26 of the scraper bowl 22 is pivoted upward, such as when the scraper bowl 22 has reached a desired capacity. Alternatively, or additionally, such adjustments may be made manually, such as by actuating one or more of the machine operation controllers 56. Additional adjustments, as should be appreciated, may be made, as desired, throughout operation of the scraper 12.
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 located adjacent a cut opening of the bowl, and an apron that may be raised or lowered to effectively open or close the cut opening. Yet further, the present disclosure may be applicable to aprons, or apron assemblies, that require smooth operation and increased position resolution. 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 and apron for collecting material.
Referring generally to
Utilizing the apron 30 and hydraulic actuator assembly 62, as described herein, may provide an improved means for adjusting a position of the apron 30 relative to the scraper bowl 22. Specifically, a linear hydraulic actuator 84 may be extended, using automatic or manual actuation means, such that a rod end 94 of the linear hydraulic actuator 84 exerts a linear force on a drive block 96. The drive block 96 translates the linear motion into rotary motion, by engaging inwardly extending projections 120 and 122 with a helical groove 124 of a drive shaft 86, causing rotation of the drive shaft 86. As the drive shaft 86 rotates, a first drive gear 88 and a second drive gear 90, supported on the drive shaft 86, also rotate. Such rotation, in a first direction, causes the first drive gear 88 to engage a first vertically aligned arcuate gear surface 76 of the apron 30, and the second drive gear 90 to engage a second vertically aligned arcuate gear surface 78 of the apron 30, thus driving the apron 30 upward.
Similarly, when the linear hydraulic actuator 84 is retracted, using automatic or manual actuation means, the drive block 96 causes rotation of the drive shaft 86 in a second, or opposite, direction. Such opposite rotation causes the drive gears 88 and 90 to engage vertically aligned arcuate gear surfaces 76 and 78, respectively, to drive the apron downward, to a closed position. Such an actuation means, as described herein, may provide improved actuation of apron 30. Specifically, the hydraulic actuator assembly 62 may provide smooth operation and increased position resolution of the apron 30, relative to the scraper bowl 22. In addition, the components of the hydraulic actuator assembly 62 may provide an actuation means that satisfies strict spatial constraints. Such a hydraulic actuator assembly 62 may have a variety of uses, in addition to apron actuation, especially in machines that are already equipped with hydraulic systems and have strict spatial requirements for actuation mechanisms.
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.
