Burning ring and head nut connection for gyratory crusher mantle

Information

  • Patent Grant
  • 6299083
  • Patent Number
    6,299,083
  • Date Filed
    Wednesday, December 1, 1999
    25 years ago
  • Date Issued
    Tuesday, October 9, 2001
    23 years ago
Abstract
The head nut assembly for gyratory crusher which includes a shaft having a lower portion, a tapered middle portion and a threaded upper portion. The threaded upper portion extends above the tapered portion. A mantle encompasses the middle tapered portion and has a correspondingly tapered internal side. The internal side is in generally continuous supportive engagement with the shaft middle portion. The mantle additionally has an upper side. A head nut is threadably secured to the upper portion of the shaft. The head nut has a lower face, where at least one bore extends upwardly into the lower face. An annular ring is disposed around the shaft between the mantle and the head nut. The ring has a lower surface coupled with the upper side of the mantle so as to prevent relative rotational movement between the mantle and the ring. An upper surface on the ring is contiguous with the lower face of the head nut. At least one key is disposed between the head nut and the annular ring. The key is completely captured inside the head nut bore and acts to couple the ring to the head nut and prevent relative rotational movement between the ring and the head nut.
Description




BACKGROUND OF THE INVENTION




Gyratory type crushers are used in the mining industry for reducing ore to a predetermined size for further processing. These style of crushers have taken over most large hard-ore and mineral-crushing applications which has made them an integral part of the mining industry. Typically, a gyratory crusher comprises a stationary conical bowl (or mortar) which opens upwardly and has an annular opening in its top to receive feed material. A conical pestle, opening downwardly, is disposed within the center of the bowl. The pestle is eccentrically oscillated for gyratory crushing movement with respect to the bowl. The conical angles of the pestle and bowl are such that the width of the passage decreases towards the bottom of the working faces and may be adjusted to define the smallest diameter of product ore. The oscillatory motion causes impact with the pestle and bowl, as a piece of ore is caught between the working faces of the bowl and pestle. Furthermore, each bowl and pestle includes a liner assembly replaceably mounted on the working faces, these liners define the actual crushing surface.




The pestle is formed by the liner, called a mantle fitted around the outside of a main shaft. The mantle provides a replaceable wearing surface. A threaded section on the shaft (or a threaded sleeve fit over the shaft) above the tapered portion of the shaft is provided for receiving a head nut. The head nut forces the mantle downward onto the tapered portion of the shaft, and is forceably tightened against the top of the mantle. Tightening prevents relative rotational movement between the head nut and the mantle. When the crusher is put into operation, the large forces involved in crushing stone cause a differential rotational movement between the shaft and the mantle. The head nut on the threaded section of the shaft is also caused to rotate relative to the shaft, in a direction which acts to further tighten the head nut onto the mantle. Thus, the rotational movement of the head nut relative to the shaft causes a large force to be transmitted in a downward direction from the head nut so as to forceably wedge the mantle onto the tapered portion of the shaft, securing the mantle to the shaft. The force also causes the bottom surface of the head nut to be pressed tightly against the top surface of the mantle such that the frictional force between the head nut and the mantle is quite large.




The frictional force between the head nut and the mantle makes it difficult to loosen the head nut by turning. Additionally, during operation of the crusher the crushing surface of the mantle is subjected to a hammering action by repeated impact of the rock or other material being crushed. This hammering action causes the working surface of the mantle to expand by cold working. The expansion of the mantle works to increase the fictional force between the head nut and the mantle. The cumulative effect of the tremendous frictional force between the head nut and the mantle is that it becomes impossible to loosen the head nut by turning it.




It is, however, necessary to remove the head nut when the mantles become worn and need replacing. Since it is not practical to loosen the head nut by turning, it must be cut from the threaded section of the shaft (as with a cutting torch). Removing the head nut in this manner damages the head nut beyond repair so that it cannot be used again. The threaded section of the shaft (or sleeve) is also easily damaged when removing the head nut in this fashion, such that the threaded shaft must be repaired, or possibly replaced. Thus, the cost associated with removing the head nut to replace worn mantles becomes excessive.




A solution to this problem proposed in prior art is to provide a burning ring between the mantle and the head nut. The burning ring is adapted so as to engage to the upper surface of the mantle and the lower surface of the head nut. When the mantle is being replaced, the burning ring is cut with a cutting torch, relieving the frictional forces bearing on the head nut. The threaded portion of the head nut may then easily be unscrewed from the shaft and the mantle can be removed.




The main method taught in prior art of affixing the burning ring to the head nut as well as the burning ring to the mantle is using keying systems. Keys are placed between the surfaces of the head nut and burning ring and between the head nut and the mantle. Typically, the keys are inserted between the components of the head nut assembly (head nut, burning ring, top of mantle) after the components are mounted on the main shaft. A common method is to form a semicircular slot running radially on each of the interfacing component surfaces, align the slots, and then place a circular pin into the slots so as to couple the surfaces together. Other shapes of slots or grooves are also used in conjunction with a key or bolt inserted after the slotted surfaces are aligned. With this arrangement, the key must be welded to the interfacing components in order for the key to be held in place. Only small welds are possible, since large welds would be on or near the exposed crushing surfaces. If the welds are on the crushing surface they are subject to breaking, allowing the key to come loose.




Other methods of attachments utilize the key as the “cutting piece.” The “cutting piece” is cut by the operator to separate the components. All of these methods require that the key be exposed to the interior of the crusher. Using exposed keys to connect the head nut, burning ring and mantle is problematic, since the interior of the crusher is a harsh environment which very often results in the keys being knocked out from between the components, uncoupling the components.




If the interface between the head nut and the burning ring or the interface between the burning ring and the mantle become uncoupled, the self-tightening feature of the head nut is lost, since the mantle no longer transfers the twisting force (which occurs when being impacted by rock) to the head nut. The mantle can loosen from the main shaft. If the gyratory crusher is not shut off, the free spinning mantle can cause extensive damage to the crusher. The mantle may crack or break, requiring replacement, or the mantle may twist with respect to the shaft, and gouge the shaft. Alternatively, the mantle may move vertically along the shaft, causing damage to the head nut or the threads of the head nut. All of these can result in extensive repairs at a great cost and with long machine downtime. At the very least, the separation of the assembly components make it necessary to turn off the machine, remove the crushing material and replace the connection, which requires a good deal of labor and lost time.




Additionally, installation problems arise when the components must be aligned after they are mounted to the shaft of the crusher to accommodate a key. The problems occur because the head nut assembly must be tightened to prevent excess “play” between the components. The key cannot be placed between the faces of the components when too much space exists between the components. When the head nut is torqued to the proper level, the slots in the component faces may not line up to accommodate the key. The operator must then untorque the head nut, realign the components, and re-torque the head nut until the correct alignment is attained.




An alternative connecting method depicted in prior art shows the coupling of the head nut to the burning ring by welding. Although welding forms a tight bond between the components and eliminates alignment problems, distortion of the head nut can result. Distortion is caused by the heat required to weld the head nut to secure the head nut to the burning ring and also to plasma torch cut the welds to free the head nut from the burning ring. Distortion of the head nut prevents the head nut from easily being removed from the shaft, and reused. Instead, the head nut must be cut off and replaced, eliminating any advantage gained by using the burning ring in conjunction with the head nut.




BRIEF SUMMARY OF THE INVENTION




The invention is a head nut assembly for a gyratory crusher machine. The head nut assembly includes a head nut and a burning ring coupled together using a key system. The head nut assembly is threaded onto a shaft and is tightened to hold a mantle in place on the shaft




In particular, the burning ring portion of the assembly is welded to the mantle of the crusher. The head nut and burning ring are connected by dowels disposed between the contiguous surfaces of the head nut and the burning ring. The dowel is entirely captured inside the burning ring and the head nut. When the burning ring is cut, the head nut is able to freely turn in relation to the mantle.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

shows a vertical cross-sectional view of the preferred embodiment of a gyratory crusher equipped with the crusher shaft and inventive head nut assembly.





FIG. 2

shows a vertical cross-sectional view of the crusher shaft of the gyratory crusher shown in

FIG. 1

utilizing the inventive head nut assembly.





FIG. 3

shows partial cross-sectional view of the crusher shaft and inventive head nut assembly shown in FIG.


2


.





FIG. 4

shows an exploded partial view of the preferred embodiment of a gyratory crusher with the inventive head nut assembly.





FIG. 5

shows an exploded side view of an alternate embodiment of the inventive head nut assembly.





FIG. 5A

shows an exploded side view of an alternate embodiment of the inventive head nut assembly.





FIG. 5B

shows an exploded side view of an alternate embodiment of the inventive head nut assembly.





FIG. 6

shows an exploded perspective view of an alternate embodiment of the inventive head nut assembly.





FIG. 7

is a cross sectional view of the head nut assembly shown after wearing due to the crushing process.











DETAILED DESCRIPTION




A gyratory crusher embodying the invention is shown generally at


10


in FIG.


1


. The gyratory crusher includes a lower frame


12


, an upper frame


14


, a top frame


16


, and a main shaft


18


. The lower frame


12


is provided with a bottom hub


20


opening upwards, and the upper frame


14


is provided with a top hub


22


opening downwards.




The shaft


18


includes a lower journal portion


24


, a middle tapered portion


26


extending from the lower journal portion


24


and an upper journal portion


28


converging from the middle tapered portion


26


. An eccentric sleeve bearing


30


is fitted about the lower journal portion


24


. The lower journal portion


24


and the eccentric sleeve bearing


30


are disposed within the bottom hub


20


so as to be rotatable within the bottom hub


20


. A bearing sleeve


32


is fitted about the upper journal portion


28


. The bearing sleeve


32


and the upper journal portion


28


are disposed in the top hub


22


so as to be rotatable within the top hub


22


. When the eccentric


30


is rotated the shaft


18


is moved transversely with respect to its axis. Thus, the eccentric sleeve bearing


30


causes the shaft to “gyrate” or move eccentrically. Since the eccentric


30


is located in the bottom hub


20


, and the shaft


18


is locked in the top hub


22


, the travel distance of the shaft


18


decreases from the end of the shaft


18


in the bottom hub


20


to the end of the shaft


18


disposed in the top hub


22


. Additionally, the oscillating motion of the shaft


18


within the gyratory crusher causes the shaft


18


to slowly rotate.




A mantle


34


is disposed around the outside of the tapered portion


26


of the shaft


18


. The mantle


34


substantially conforms to the shape of the taper and is typically manufactured of manganese steel, although a person skilled in the art would realize that other metals may be used, including other alloy steels. The upper frame


14


surrounds the shaft


18


and mantle


34


, forming a crushing chamber


36


disposed substantially between the upper frame


14


and the mantle


34


. To operate the crusher, the crushing chamber


36


is filled with rock (or other material) through the top frame


16


. The shaft


18


is oscillated eccentrically. The eccentric motion of the shaft


18


causes the rock to be compressed between the walls of the crushing chamber (including the mantle


34


and the upper frame


14


), as well as against other rock in the crushing chamber


36


. The tapered shape of the mantle


34


, the inward sloping walls of the upper frame


14


as well as the increasing transverse movement of the shaft


18


towards the lower end of the shaft causes the area of the crushing chamber


36


to decrease as the rock falls towards the bottom of the chamber


36


. Thus, the rock is broken into smaller and smaller pieces until it is removed from the bottom of the crusher. The mantle


34


is cold worked by the impinging rock in the crushing chamber


36


, causing the mantle


34


to expand. The mantle


34


also experiences rotational forces (caused by the crushing material as it is compressed against the mantle


34


during the crushing process) counter to the rotational direction of the shaft


18


.




To support the mantle


34


on the main shaft


18


, a filler or backing material


38


(known to those skilled in the art, such as using a zincing process) is poured between the shaft


18


and the mantle


34


as shown in FIG.


2


. The filler material


38


is allowed to cool and solidify and thereby maintains a contiguous connection between the shaft


18


and the mantle


34


. The material


38


adheres to the inside of the mantle


34


, however, it does not adhere to the main shaft


18


. The filler


38


is used to provide a tight clearance between the mantle


34


and the shaft


18


, helping to secure the two pieces together. The main securing mechanism, however, is provided by connecting the upper journal portion


28


of the shaft


18


to the mantle


34


.




Bearing sleeve


32


extends coextensively with the upper journal portion


28


of the shaft


18


, with its lower end


40


disposed proximate to the top end


42


of the tapered portion


26


of the shaft


18


. as shown in

FIG. 3

, the lower end


40


of the bearing sleeve


32


includes an externally threaded annular shoulder


44


. The threaded shoulder


44


is secured to the top end


42


of the mantle


34


through a head nut assembly


50


. The head nut assembly


50


includes an annular head nut


52


, an annular burning ring


54


and keys


56


A and


56


B. The head nut


52


is internally threaded so as to be received by the threaded shoulder


44


of the bearing sleeve


32


. Although the preferred embodiment of the invention threads the head nut


52


to the bearing sleeve


32


, a person skilled in the art would realize that other embodiments conform to the spirit of the invention, including threading the head nut


52


directly to the upper journal portion


28


of the shaft


18


. It is important to counter the rotational forces caused by the crushing action and maintain the mantle


34


in the same relative rotational position with the shaft


18


. If this is not done, the mantle


34


can gouge the shaft


18


, or break off the shaft


18


completely. The head nut


52


provides a downward force on the mantle


34


which forces the mantle


34


and filler


38


against the shaft


18


, preventing the mantle


34


from rotating with respect to the shaft


18


. Any rotational motion between the shaft


18


and the mantle


34


causes the nut


52


to tighten, adding additional downward force to the mantle


34


preventing further relative rotation.




Head nut


52


includes an internal threaded face


60


engaging the threaded bearing sleeve


32


. An external face


62


is substantially parallel and coaxial to the threaded face


60


. A lower face


64


is perpendicular and coaxial to the threaded face


60


extending between the threaded face


60


and the external face


62


. An upper face


66


is parallel to the lower face


64


and perpendicular and coaxial to the threaded face


60


, extending between the threaded face


60


and the external face


62


. In one embodiment of the invention, the head nut


52


has an outer diameter of approximately twenty-nine inches, an inner diameter of approximately twenty-four inches and a height of approximately five inches. Head nut bores


68


A and


68


B extend perpendicularly into the lower face


64


, and are disposed at diametrically opposite points of the lower face


62


(for example at noon and six o'clock as on the face of a clock). In one embodiment, each bore


68


A and


68


B has a diameter of approximately one inch and a depth of approximately three quarters of an inch.




Burning ring


54


includes a top face


70


, an outer face


72


, an inner face


74


and a bottom face


76


. The top face


70


of the burning ring


54


contiguously engages the lower face


64


of the head nut


52


. The bottom face


76


is parallel and coaxial to the top face


70


and includes a raised lip


77


which engages and centers the mantle


34


about the shaft


18


. The outer face


72


is perpendicular and coaxial to the top face


70


and extends between the top face


70


and the bottom face


76


. The inner face


74


is parallel to the outer face


72


and extends between the top face


70


and the bottom face


76


. In one embodiment, the outer diameter of the burning ring


54


is approximately twenty-nine inches, and the inner diameter is approximately twenty-five inches. Burning ring bores (or apertures)


78


A and


78


B extend perpendicularly into top face


70


through the burning ring


54


and out the bottom face


76


. Each burning ring bore


78


A and


78


B includes an inner wall


79


A and


79


B and is disposed directly below the head nut bores


68


A and


68


B respectively. Although dimensions have been provided for one embodiment of the inventive head nut assembly


50


, a person skilled in the art would realize that dimensions will vary according to the size of the gyratory crusher


10


.




The dowel shaped keys


56


A and


56


B are disposed in the burning ring bores


78


A and


78


B and extend upwardly into the head nut bores


68


A and


68


B. The keys


56


A and


56


B are typically welded into the burning ring bores


78


A and


78


B (preferably by fillet welding the bottom of each key


56


A and


56


B to the inner wall


79


A and


79


B of the burning ring bores


78


A and


78


B proximate to the bottom face


76


of the burning ring). Thus, the keys


56


A and


56


B are completely captured inside the head nut


52


and the burning ring


54


, with no part of either key


56


A and


56


B exposed to the crushing chamber


36


.




Capturing the keys


56


A and


56


B entirely within the head nut assembly


50


prevents the keys


56


A and


56


B from being subject to impingement of the crushing material. This prevents the keys


56


A and


56


B from being knocked out of bores


68


A,


68


B,


78


A, and


78


B which would allow the head nut


52


to rotate independently from the burning ring


54


causing the problems described above. Additionally, the use of the dowels


56


A and


56


B to key the head nut


52


to the burning ring


54


prevents the need to weld to the head nut


52


. Welding to the head nut


52


can distort the head nut


52


requiring the head nut


52


to be cut off when it is to be removed, possibly damaging the threaded shoulder


44


of the bearing sleeve


32


in the process. Damage to the head nut


52


can thereby result in a great expense and associated downtime while the head nut


52


, bearing sleeve


32


and possibly the shaft


18


are repaired.




The bottom face


76


of the burning ring


54


is generally contiguous with an upper surface


80


of the mantle


34


. Mantle upper surface


80


is typically wider than the bottom face


76


of the burning ring


54


so as to form a shoulder


82


with the burning ring outer face


72


. Preferably, a fillet weld


84


is used to attach the burning ring


54


to the mantle


34


along the shoulder


82


. Welding the ring


54


to the mantle


34


connects the mantle


34


to the head nut assembly


50


during operation of the crusher


10


. Since the burning ring


54


will be cut off during change out of the mantle


34


, distortion due to welding is not a concern. Welding the burning ring


54


is a more reliable method of securing the ring


54


to the mantle


34


than using a keying method since it eliminates any possibility of keys coming loose and allowing the ring


54


to rotate relative to the mantle


34


. Additionally, welding the ring


54


to the mantle


34


has the advantage of allowing the head nut assembly


50


to be tightened onto the mantle


34


without the necessity of aligning grooves or slots for keys. The head nut assembly


50


is fully torqued onto the mantle


34


and the ring


54


is fillet welded to the mantle


34


. Although the preferred embodiment of the invention welds the mantle


34


to the burning ring


54


, a person skilled in the art would realize that the mantle


34


can be keyed to the burning ring


54


.




The inventive head nut assembly


50


has the additional advantage of being easily manufactured and installed in the crusher


10


. The only machining required on the head nut


52


and the burning ring


54


for the keying system are the bores


68


A,


68


B,


78


A and


78


B which are easily machined using a drill-press. The dowels


56


A and


56


B do not need to be press fitted into the bores


68


A,


68


B,


78


A and


78


B in order to maintain a secure connection between the head nut


52


and the burning ring


54


, since they can be welded to the inner walls


79


A and


79


B of the burning ring bores


78


A and


78


B. Thus, standard machining tolerances can be used.




The exploded view shown in

FIG. 4

illustrates the method used to install the head nut assembly


50


. The mantle


34


is set on the main shaft


18


and shimmed into position. The keys


56


A and


56


B are disposed into bores


68


A,


68


B,


78


A and


78


B. For convenience, the head nut


52


and the burning ring


54


can be lightly tack welded together (although this is not necessary). Tack welding the head nut


52


does not distort the nut


52


since heat is only applied to the nut


52


for a short amount of time. The keys


56


A and


56


B are fillet welded to the inner walls


79


A and


79


B of the burning ring bores


78


A and


78


B. The assembly of the head nut assembly may occur where it is manufactured (i.e. a burning ring assembly including the keys


56


A and


56


B welded in place and, if desired, the head nut


52


and burning ring


54


back welded together), limiting the amount of work that needs to be done at the crusher


10


site (eliminating crusher downtime). A person skilled in the art would realize, however, that the head nut assembly may take place at the crusher location.




The head nut assembly


50


is screwed onto the main shaft


18


until the raised lip


77


on the bottom face


76


of the burning ring


54


engages the inner diameter of the mantle


34


. The lip


77


acts to center the mantle


34


about the main shaft


18


as the head nut assembly


50


is tightened onto the mantle


34


. The backing material


38


is poured and allowed to harden and the burning ring


54


is fillet welded to the mantle


34


.




When the mantle


34


is worn out and needs to be replaced, the burning ring


54


is cut horizontally (i.e. with a plasma torch), relieving pressure against the head nut


52


and allowing it to be unscrewed and re-used. The old mantle is removed and a new mantle is positioned about the shaft


18


. The above process is then repeated using a new burning ring attached to the head nut


52


with new keys.




The preferred embodiment of the invention secures the keys


56


A and


56


B into the burning ring


54


bores


78


A and


78


B by welding them to the inner wall


79


A and


79


B. Welding has the advantage of fixing the keys


56


A and


56


B into place, eliminating tipping of the keys


56


A and


56


B inside the bores


68


A,


68


B,


78


A, and


78


B. Tipping of the keys


56


A and


56


B causes greater shear forces on the keys


56


A and


56


B increasing the possibility of key breakage and separation of the nut


52


from the ring


54


. An alternate embodiment of the invention would place keys


156


A and


156


B in blind bores


168


A,


168


B,


178


A, and


178


B drilled into the burning ring


54


, as shown in FIG.


5


. The keys


156


A and


156


B may be press fit into the bores


178


A and


178


B to eliminate tipping of the keys


156


A and


156


B. An additional alternative configuration would utilize head nut bores


180


A and


180


B which extend completely through the head nut


52


, and blind burning ring bores


182


A and


182


B in the burning ring


54


, as shown in FIG.


5


A. The keys


156


A and


156


B are captured in bores


180


A,


180


B,


182


A and


182


B. The keys


156


A and


156


B are then fillet welded into the head nut bores


180


A and


180


B (once again, the short welding time to weld the two keys


156


A and


156


B to the head nut


52


does not cause head nut


52


distortion). Still another alternate embodiment is to insert threaded keys


190


A and


190


B into threaded burning ring bores


192


A and


192


B disposed in the burning ring


54


as shown in FIG.


5


B. The threaded keys


190


A and


190


B eliminate tipping of the keys


190


A and


190


B in the burning ring bores


192


A and


192


B. The upper end of the keys


190


A and


190


B extend into blind head nut bores


194


A and


194


B, disposed in the head nut


52


, locking the head nut


52


rotationally with respect to the burning ring


54


.




Although the preferred embodiment uses two keys to connect the burning ring


54


to the head nut


52


, a person skilled in the are would realized that additional keys may be used, as shown in FIG.


6


. Keys


256


A,


256


B,


256


C and


256


D are positioned between burning ring bores


278


A-


278


D and head nut bores


268


A-


268


D so that the keys


256


A-


256


D are not exposed to crushing material. Other key configurations utilizing additional keys spaced in various positions around the head nut assembly


50


may be used to secure the head nut


252


to the burning ring


254


. Additionally, a person skilled in the art would realize that other key shapes may be utilized. For example, square, rectangular, or triangular pins may be used.




An additional advantage of the inventive head nut assembly


50


is the use of captured keys


56


A and


56


B inside the head nut


52


as an indication of head nut


52


wear. Although the head nut


52


does not wear as quickly as the mantle


34


, eventually the head nut


52


does need to be replaced. An easy method for the operator to determine when this change-out needs to take place is when the keys


56


A and


56


B begin to show through the external face


62


of the head nut


52


, as shown in FIG.


7


.




The innovative method of positioning the keys


56


A and


56


B in a captured position between the head nut


52


and the burning ring


54


serves to maintain a reliable connection in the head nut assembly


50


. Repair and down time costs are thereby substantially reduced, and maintenance is more easily scheduled and performed.




Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.



Claims
  • 1. A head nut assembly for a gyratory crusher, the crusher including a shaft having a lower portion, a tapered middle portion and a threaded upper portion extending above the tapered portion and a mantle encompassing the tapered middle portion having a correspondingly tapered internal side and an upper side wherein the internal side is in generally continuous supportive engagement with the shaft middle portion, comprising:a head nut threadably secured to the upper portion of the shaft, having a lower face, wherein at least one bore extends vertically upward into the lower face; an annular ring disposed around the shaft between the mantle and the head nut, the ring having a lower surface secured to the upper side of the mantle so as to prevent relative rotational movement between the mantle and the ring, and an upper surface wherein the upper surface is contiguous with the lower face; and at least one key disposed between the head nut and the annular ring so as to rotationally couple the head nut to the annular ring, wherein the key is completely captured inside the head nut and annular ring.
  • 2. The apparatus of claim 1 wherein the key is welded to the annular ring.
  • 3. The apparatus of claim 2 wherein the annular ring lower surface is welded to the upper surface of the mantle.
  • 4. The apparatus of claim 3 wherein the key is in the shape of a dowel.
  • 5. The apparatus of claim 1 wherein the annular ring further comprises:at least one aperture extending downwardly into the upper surface, wherein the key is disposed in the aperture, extending upwardly into the head nut bore, so as to completely capture the key inside the bore and aperture.
  • 6. The apparatus of claim 5 wherein the annular ring lower surface is welded to the upper side of the mantle.
  • 7. The apparatus of claim 6 wherein the key is in the shape of a dowel.
  • 8. The apparatus of claim 1 wherein the annular ring further comprises at least one aperture having an internal wall, extending downwardly into the upper surface, extending through the annular ring to the lower surface, wherein the key is disposed in the aperture extending upwardly into the head nut bore.
  • 9. The apparatus of claim 8 where the key is welded to the internal wall of the aperture.
  • 10. The apparatus of claim 9 where the annular ring lower surface is welded to the upper side of the mantle.
  • 11. The apparatus of claim 10 wherein the key is in the shape of a dowel.
  • 12. A head nut assembly for a gyratory crusher comprising:a head nut having a lower face and a bore extending perpendicularly into the lower face; a burning ring having an upper side and an aperture extending perpendicularly into the upper side, wherein the upper side is contiguous with the lower face; and a key disposed within the aperture and extending into the bore, wherein the key is completely captured within the head nut and the burning ring.
  • 13. The head nut assembly of claim 12 wherein the burning ring further comprises:a lower side, wherein the aperture extends through the burning ring to the lower side, and the key is welded to the burning ring.
  • 14. The head nut assembly of claim 13, wherein the key is dowel shaped.
  • 15. A burning ring for use with a head nut in a gyratory crusher, the head nut having a lower face and a bore extending perpendicularly into the lower face, the burning ring comprising:a lower surface and an upper surface, wherein the upper surface is contiguous with the lower face; an aperture extending perpendicularly into the upper surface through the burning ring, and out the lower surface; and a key having a first end for positioning in the aperture and a second end for extending upwardly into the bore so that when the burning ring is positioned adjacent the head nut the key is completely captured inside the aperture and the bore and acts to couple the ring to the head nut.
CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority from U.S. Provisional Application Ser. No. 60/136,899 filed Jun. 1, 1999 for “Burning Ring for Gyratory Crusher Mantle” by Donald J. Polinski and Thomas Edward Vogltanz.

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Provisional Applications (1)
Number Date Country
60/136899 Jun 1999 US