The present invention relates to balancing assemblies for rotating members for use in removing obstructions from a work site. More particularly, the invention relates to self aligning balancing assemblies for large cylindrical cutting members supported on a trailer.
The present invention is directed to a device for crushing a hard surface. The device comprises a frame, a linear actuator, a rotatable cutting drum and an engine. The frame comprises a first ground engaging member, a second ground engaging member and a pivot point disposed between the first ground engaging member and the second ground engaging member, wherein a pivot axis of the pivot point is substantially horizontal. The linear actuator is disposed on the frame to change a height of the pivot point. The rotatable cutting drum is disposed on the frame such that a height of the rotatable cutting drum is changed when the height of the pivot point is changed. The engine has a weight and is disposed on the frame above the cutting drum such that the weight of the engine is substantially transferred into the ground by the cutting drum.
Cylindrical drum assemblies are generally massive and require a high torque motor or engine to initiate rotation of the drum and to maintain rotation during operation. Although the drum assemblies are rotated at a low number of revolutions per minute (rpm), the high mass of the drum results in several problems. First, the centrifugal force produced by the rotation of a high mass structure is extreme even at low rpm and necessitates a robust, heavy duty gear box to transmit the rotational force of the motor to the drum. Often, a separate gear box and motor assembly is used on each of the opposing ends of the axis about which the drum rotates. In such a configuration, one gear box and motor assembly is structured for clockwise rotation and the opposing gear box and motor assembly is structured for counter-clockwise rotation so that their rotational force combines to rotate the drum in a single direction. These gear box and motor assemblies distribute the force required to rotate the drum so that less robust gear boxes and motors may be used.
Second, if the drum is unbalanced around the axis of rotation so as to produce an oscillating radial force, this radial force will excessively wear the gear box and motor so as to cause premature failure. When using a pair of opposing gear box and motor assemblies, the alignment of the centerline of both assemblies reduces radial forces and resultant wear on the bearings of these assemblies; otherwise the misalignment may cause premature failure of the bearings. This alignment may be achieved by precise machining and balancing of the drum. However, such machining and balancing for drums with diameters in excess of 12 inches and lengths in excess of five feet requires large, heavy duty, and expensive machines to turn the massive drums and cut away excess metal. High precision is difficult to attain when dealing with such heavy, bulky structures. Additionally, the removal, shipping, and replacement of the drum in its installed location is expensive in terms of required man power. The removal, shipping, and replacement can also be further complicated by the fact that machines employing such heavy drums, e.g., road equipment, are often used in remote locations where transportation is difficult and knowledgeable maintenance personnel are unavailable.
Third, during use, the drum is loaded by the work against which it rotates, e.g., the road surface for a cutting drum or the uneven winding of paper on a takeup drum in a paper plant. This loading coupled with the massiveness of the drum causes a small amount of deflection which also results in unbalancing of the drum assembly.
Fourth, even if the drum is perfectly balanced about its axis of rotation, the gear box must be positioned precisely so that the shaft is exactly colinear with the axis of rotation. This requires that the mounting surfaces for the gear box must be machined to very precise tolerances. On a large machine, this is very difficult and expensive, and, while it improves the initial misalignment, it does not help with the deflection problem.
As can be seen, there is a need for a method and apparatus to maintain the balance of a massive rotating drum assembly, reduce the requirement for close precision in the physical balancing process for the drum, and dynamically adjust for in-use deflection of the drum so that balance about the axis of rotation is maintained.
Finally, while such drum assemblies have been used in conjunction with dedicated machines, it would be advantageous to utilize such assemblies with a weighted, pull-behind trailer that could be pulled behind a tractor or similar heavy construction vehicle. Thus, while the overall weight of the trailer will be less as compared with the weight of a dedicated machine, placement on a trailer would allow the engine, fuel tank, and other heavy elements to be placed directly above the drum, increasing the stability of the drum and reducing the hydraulic load required.
The device of the figures generally is used for grinding rock and hard earth for the preparation of road beds and for removing obstructions, such as brush and trees, from a worksite. The trailer comprises a frame and a rotatable cutting member, or drum, which is supported on the frame at both ends of the cutting member. A gear box and motor are located at one and/or both ends of the cutting member and are covered by a protective panel attached to an end plate. The surface of the cutting member supports cutting blades or teeth for removing obstructions or undesired materials as the drum rotates.
With reference now to
The battery 18 provides direct electric current to components of the crushing assembly, including the engine 14 for starting purposes. Further, the battery 18 may power actuators located on the crushing assembly 10 which may control the pivot frame 20, the height and rotation rate of the drum assembly 100, sensors (not shown), etc.
The pivot frame 20 defines a first end 28 and a second end 29. The pivot frame 20 is attached to the frame 12 at a pivot point 30 located at the first end 28. The pivot point 30 has a substantially horizontal pivot axis. The pivot frame 20 is actuated by a pivot frame cylinder 32 attached to the pivot frame between the first end 28 and the second end 29. The pivot frame cylinder 32 is attached at a first end to the frame 12 and at a second end to the pivot frame 20, and extendable between a first and second position. As shown in
The ground supporting members 22 are located on opposing ends of the crushing assembly 10 and adapted for translation of the crushing assembly and its component parts across the ground 11. As shown, the ground supporting members 22 comprise wheels, though a tracked. system may be utilized without departing from the spirit of the invention. As shown, the ground supporting members 22 comprise front wheels 40 and rear wheels 42. The rear wheels, as shown, are located on the pivot frame 20 and attached to the pivot frame by a pivot frame pin 43, The front wheels 40 are located on the hitch portion 44 of frame 12. Preferably, the drum assembly 100 is located closer to the pivot point 30 than front wheels 40 to reduce hydraulic load required to raise the drum assembly 100 completely off the ground 11. The hitch portion 44 comprises a hitch 46 and an attachment point 48. The hitch 46 allows the crushing assembly 10 to be attached to a tractor (not shown), truck, or other vehicle for providing motive translational force to the crushing assembly. The attachment point 48 provides attachment between the central frame 21 and hitch portion 44. The attachment point 48 may provide for articulation between the central frame 21 and hitch portion 44 to allow for a reduced turning radius of the crushing assembly 10. One of skill will appreciate that a vertical pivot may alternatively be utilized between the central frame 21 and the hitch portion 44 to allow the same vertical displacement of the cutting drum assembly 100 as pivot frame cylinder 32.
With reference to
Referring now to
The cutting drum assembly 100 comprises a plurality of skid shoes 155 located on the frame 120. The skid shoes 155 provide a surface of contact between the ground and the cutting drum assembly 100. Preferably, the skid shoes 155 may be adapted such that a distance between a centerline of the cutting member 130 and the ground may be manipulated by an orientation of the skid shoes. More preferably, the orientation of the skid shoes 155 may be manipulated by control on the crushing assembly 10 (
The cutting drum assembly 100 may be adjustable relative to the central frame 21 (
With reference again to
The frame 120 provides support for other elements of the cutting drum assembly 100. The support structure 160 is constrained to contain self-aligning mount 200. The mount 200 is non-rotatably supported within the support structure 160 by radially extending retaining members or protrusions 260 adapted to mate with the gaps 270 in the support housing 160. The mount 200 may comprise an edge 201 that is a sectional ellipsoid or sphere. The protrusions 260 are sized within the gaps 270 such that the mount 200 is moveable about three axes relative to the support structure 160, limited only by the tolerance of the gaps 270 relative to the protrusions 260. The protrusions 260 are sufficiently sized such that rotational forces due to operation of the motor 202 and the cutting member 130 are fully transferred to the frame 120, while allowing the mount 200 some tolerance of motion about at least one axis. Preferably, some tolerance of motion is allowed about at least three axes. The edge 201 further allows freedom of movement between the support structure 160 and mount 200.
The motor 202 is provided inside the cutting member 130 to rotate the cutting member. Alternatively, the motor may comprise hydraulic or other components adapted to provide a rotational three to the cutting member 130. The motor 202 may be powered by the engine 14 (
Referring now to
As shown, the support housing 160 comprises four (4) of the gaps 270 equally spaced about the support housing. Alternatively, a different number of gaps 270 or spacings thereof may be utilized, as long as those gaps correspond to the features of the mount 200 (
It should be noted that contact operation of the cutting drum assembly 100 may cause the teeth to become deflected or broken. Deflected or broken teeth 132 (
Turning now to
One skilled in the art will appreciate the cutting drum assembly 100 may comprise only one motor 202 at one end of the cutting member 130. In this embodiment, the second mount 200B located at the second end of the cutting member 130 would comprise a bearing such that the second end of the cutting member would rotate freely relative to the second mount, while allowing the second mount to move about a plurality of axes relative to the support housing 160 as discussed above with reference to
The first motor 202 is adapted to operate with sufficient horsepower to rotate the cutting member 130 at an operational rate. For example, the motor may provide an operational rate of thirty-five horsepower in an application utilizing light equipment. Alternatively, heavy-duty applications of the present invention may require an operational rate of five hundred forty horsepower or more. The preferred rotational velocity of the cutting member 130 provided by the motor 202 for crushing surface rock is slow, perhaps 10 to 100 rpm. However, other speeds may be advantageous for other applications of the cutting drum assembly 100, and thus other speeds of the cutting member 130 are anticipated.
With reference to
One of ordinary skill in the art will appreciate that modifications may be made to the invention without departing from the spirit herein. For example, a weight can be provided above the cutting drum assembly 100 and the motor 202 powered by an engine on the tractor pulling the crushing assembly 10.
This application claims the benefit of provisional patent application Ser. No. 61/971,871 filed on Mar. 28, 2014, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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61971871 | Mar 2014 | US |