Patent Grant
7090159
1. Field of the Invention
The present invention pertains to the art of impact crushers and, more particularly, to a center feed disk for an impact crusher that, after a first side surface has become worn, can be inverted to make use of an opposing, second side surface for operating the impact crusher.
2. Discussion of the Prior Art
There are a wide variety of impact crushers currently employed to reduce the size of large earth materials to smaller sized aggregate. Typically, a flow of large earth materials is dropped or fed onto a rotating feed disk that, using centrifugal force, disperses the large earth materials through the impact crusher onto crushing components. Generally, the crushing components include impeller shoes and anvils that are radially positioned about the feed disk. In any event, impact crushers reduce large aggregate earthen materials to aggregate sizes and shapes to meet the needs of, for example, the construction industry as ingredients for cement and the like.
The components of an impact crusher that are exposed to a material flow are subject to wear. The wear is essentially caused by abrasion, decomposition, fracture, impact, grinding and the like. In general, the wear results from the velocity, acceleration and composition of the material flow that is directed onto the components of the impact crusher. Over time, the wear reaches a point which mandates that one or more of the impact crusher components be replaced. One component that is prone to wear is the feed disk. A typical feed disk can process about 2,500 tons of material before becoming worn and in need of replacement. Thus, in an impact crusher that can process 42 tons of material an hour, the average life of a feed disk would be approximately 60 hours. Accordingly, every 60 hours or so, the feed disk must be replaced. As only one surface of the feed disk is usable, the costs associated with feed disk replacement are high.
Based on at least these reasons, there exists a need in the art for a feed disk that has a longer service life. More specifically, there exists a need in the art for a feed disk that can be inverted so that both surfaces of the disk can be used in operating the impact crusher before the disk is discarded.
The present invention is directed to a center feed disk and an impact crusher that are used to reduce the size of large earth materials to smaller sized aggregate. The impact crusher includes an impeller table assembly having a rotating impeller table. The impeller table includes an outer edge portion, as well as an inner edge portion that define an impeller surface. The impeller table assembly also includes a plurality of shoes that are arranged about the impeller surface. The shoes function to catch the large earth materials and throw them, with tremendous centrifugal force, radially outwardly against fixed anvils. Large earth materials are actually dropped onto a rotating, center feed disk that receives and directs the large earth materials toward the shoes and ultimately onto the anvils. Upon impacting the fixed anvils, the large earth materials break up, under their own momentum, into smaller aggregate material.
In accordance with the invention, the center feed disk includes a peripheral edge portion, a first face and an opposing, second face. A central bore extends through the first and second faces and is surrounded by first and second countersunk pockets provided in each of the first and second faces respectively. A fastener, having a shaft portion and a head portion, is inserted through the central bore to secure the center feed disk for rotation with the impeller table. Preferably, the fastener is sized such that, when fully engaged, the head portion is completely recessed within the countersunk pocket. Once the first face of the center feed disk exhibits sufficient wear, the center feed disk can be removed, inverted and re-mounted to the impeller table such that the second face is then used to receive and direct the large earth materials toward the shoes to be crushed into aggregate. In this manner, an overall service life of the center feed disk can be increased by as much as two times.
In further accordance with the invention, the center feed disk is formed from a wear-resistant material, such as a chromium iron (ASTM A532/A532M-93a standards) alloy or a carbide, preferably cemented tungsten carbide. Experience has shown that chromium, at levels of 23–30%, produces advantageous wear-resistant qualities. In addition, prior to inverting the center feed disk, smoothing and preferably improving the balancing of the disk may be employed. Because the disk rotates at high speeds, some as high as approximately 2000 rpm, an out-of-balance disk could cause substantial vibration. Thus, prior to re-mounting, the wear regions are preferably filled with a resin, such as liquid silicone, preferably a high density material similar to LAB/metal™ or having greater density to provide a uniform surface in the event of uneven wear, and preferably substantially minimize, an out-of-balance condition. LAB/metal™ is marketed by Alvin Products Inc., of Lawrence, Mass.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
With initial reference to
In general, the above-described structure is provided for the sake of completeness and to enable a better understanding of the overall invention. One key aspect of the present invention is particularly directed to a center feed disk 40 located centrally witin impeller table assembly 6. In operation, center feed disk 40 is rotated together wit impeller table assembly 6. A flow of large earth materials is dropped onto center feed disk 40 and a tremendous centrifugal force, developed by rotating center feed disk 40, causes the flow of large earth materials to be deflected radially outwardly toward impeller shoes 16. Impeller shoes 16 catch the large earth materials and throw them violently against fixed anvils 24. When the large earth materials strike fixed anvils 24, the earth materials crack, under the force of their own momentum, into relatively uniform, often cubical pieces, that fall down onto a conveyor (not shown) or other suitable output device. Due to the extreme forces involved, center feed disk 40 must be formed from a wear-resistant material to provide an acceptable service life. In accordance with one form of the invention, the wear-resistant material is a metal alloy. A preferred metal alloy is a high chrome iron alloy having approximately 23–30% chromium (see ASTM A532/A532M - 93a (reapproved 1999)ε1). In accordance with another form of the invention, center feed disk 40 is formed from carbide or other ceramic composite, preferably cemented tungsten carbide. Regardless of the particular material, center feed disk 40 must resist, as long as possible, the constant wear from large earth materials being fed into impact crusher 2.
As best shown in
As best represented in
As indicated above, over time, wear begins to develop on first face 44, such as indicated by an annular notch 74 in
In accordance with the most preferred form of the invention, prior to inverting and remounting of center feed disk 40, annular notch 74, as well as other imperfections (not shown) on first face 44, is filled with a resin, or preferably a high density material such as LAB/metal™, to smooth and improve the balance and level center feed disk 40. Because center feed disk 40 rotates at speeds upwards of 2000 RPM, the various imperfections, and particularly annular notch 74, in first face 44 can cause significant vibrations to impact crusher 2. Therefore, in order to smooth the surface of and improve the balance center feed disk 40, a resin material 78 is applied to first face 44 and allowed to harden to resurface first face 44. The resin material may contain a filler material such as aluminum, iron, lead, tungsten or tungsten carbide to further improve the balance of the disk.
Prior to remounting center feed disk 40 to impact crusher 2 with second face 46 exposed to the material, a spacer or shim 84 can be placed upon first face 44 as indicated in
In one particular embodiment of the invention, a cemented tungsten carbide center feed disk 40 was utilized for crushing 120,000 tons of earth materials before being removed and inverted. When inverted, a steel spacer 84 was employed. In any event, it should be readily apparent that the combination of the materials used to make center feed disk 40 and the ability to invert center feed disk 40 in accordance with the invention results in a dramatic increase in the useful life of center feed disk 40. Correspondingly, the costs associated with operating impact crusher 2 and its related downtime are significantly reduced such that an extremely advantageous and commercially viable arrangement is established.
All documents, publications and patents referred to herein are hereby incorporated by reference.
Although described with reference to a preferred embodiment of the present invention, it should be readily apparent to one of ordinary skill in the art that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, it should be understood that the use of the terms first and second surfaces is for the sake of clarity and is not intended to limit the scope of the present invention. In general, the invention is only intended to be limited to the scope of the following claims.
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| Number | Date | Country | |
|---|---|---|---|
| 20050211810 A1 | Sep 2005 | US |
