Abstract:
The apparatus is a gyratory crusher in which all the wear parts can be removed and replaced from the top of the crusher, thus eliminating the need to remove large, heavy parts from below the crusher. This is accomplished by constructing the crusher so that the eccentric and the piston assembly can be lifted up and out sequentially. The piston assembly then includes all the wear parts within the lowest assembly, the hydraulic support, so that those parts can be replaced without access to the underside of the crusher. If necessary, the hydraulic support within which the piston assembly is held can also be removed from above the crusher.

Description:
BACKGROUND OF THE INVENTION 
     This invention deals generally with gyratory crushers, and more specifically with a gyratory crusher for which all regular service and parts replacement can be accomplished from above the crusher. 
     Gyratory crushers are well established machines that are used for crushing rocks, ore, and other materials. They are very large and their basic structure comprises a bowl shaped as a cone with the wider end of the cone near the top of the crusher. A conical head assembly is located on the axis of the bowl, and the head assembly is oriented so that its smaller dimension is at the top of the crusher. To perform the crushing action, independent motions are applied to the conical head assembly. The first is rotation and the second is gyration. 
     In the typical gyratory crusher, large material is fed into the top between the large opening of the bowl and the small end of the head assembly where the volume is largest. The gyration of the head assembly is furnished by an eccentric drive, the rotation is driven by a gear, and vertical support and minor vertical adjustment is furnished by a hydraulic support. All these parts are located at the bottom of the crusher at the bottom of the conical head assembly. The combination of the rotation and the gyration applies forces that crush the pieces of material, and they fall lower into the reduced space within the bowl as they are reduced in size. Ultimately the material leaves the crusher through openings at the bottom of the crusher. 
     The hydraulic support assemblies on most gyratory crushers are large, heavy hydraulic cylindrical casings with robust bronze bushings, and they are located below the head assembly and the eccentric and gear drives. To service the wear parts of such a hydraulic support, it needs to be removed from the crusher, and to do this the assembly must be unbolted from the crusher frame and lowered onto a cart or other device which can move it out from beneath the crusher. This procedure is dangerous and time consuming because it requires personnel to be beneath the crusher to guide the movement of the hydraulic support while the crusher and the hydraulic support are being supported. Working below the crusher can expose personnel to hazards such as a poor visibility, poor communication, falls and tripping, high dust exposure, and rock falls. 
     It would be very beneficial to have a gyratory crusher that did not require access below the machine for scheduled and emergency service of the hydraulic support assembly and for removal of the eccentric drive, and other equipment. 
     SUMMARY OF THE INVENTION 
     The gyratory crusher of the present invention provides access for virtually all service through the top of the machine. The invention thereby eliminates the risks to personnel from working below the crusher, because the conical head assembly, the eccentric assembly, and the hydraulic support assembly, which comprises a piston assembly within and supported by a cylindrical support, are all removable through the top of the crusher. Furthermore, in the preferred embodiment the hydraulic support assembly is constructed so that the internal piston assembly contains essentially all the designed wear parts typically located within the hydraulic support assembly. In prior art crushers some of these wear parts are designed to be located on the cylindrical support. Such a preferred embodiment limits the need to remove the cylindrical support of the hydraulic support assembly in order to replace the designed wear parts. Of course, if necessary the cylindrical support also is removable through the top of the crusher. 
     To accomplish this top access feature, the eccentric assembly and the cylindrical support are each constructed to pass through the crusher frame structure. The basic configuration of each of the eccentric assembly and the cylindrical support is a cylinder with a circumferential lip protruding outward from the top edge of the cylinder. Such a structure permits each of these parts to be supported by a circumferential ledge built into the crusher. The other requirement to assure that the parts can be lowered into place and removed from above the crusher is that the outside diameter of the uppermost part, the eccentric assembly, must be larger than the outside diameter of the cylindrical support which must pass through the location formerly occupied by the eccentric assembly after the eccentric assembly is removed. That is, the cylindrical support must be sized to pass through the opening left after the eccentric assembly is removed. 
     The hydraulic assembly, comprising the cylindrical support and piston assembly, is located below the crusher and constructed with a tight fit and seal. The piston assembly fits within the cylindrical support and can be removed from within the cylinder support. The piston assembly can be removed with the eccentric assembly in place or with the eccentric assembly first removed. 
     The preferred embodiment of the present invention provides the particular benefit of having all the designed wear parts of the hydraulic support installed on the piston assembly. These include a piston wear ring, one or more hydraulic seals, and upper and lower piston bushings, with the latter two parts normally located on prior art cylindrical supports. The resulting advantage of this design is that that all such wear parts can be replaced at the same time, such as when the piston assembly is at a workbench. The piston assembly and wear parts can be serviced without requiring removal of the cylinder housing. In fact, the least time consuming service method is to have another piston assembly with new wear parts available at the crusher, and to replace the whole piston assembly immediately, so the replacement of the wear parts can take place independently of servicing the crusher. 
     The combination of service access from the top of the crusher and all the designed wear parts on only one piston assembly thus provides an apparatus which is both exceptionally safe and very efficient to service. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cross section view of the preferred embodiment of the gyratory crusher of the invention. 
         FIG. 2  is a partial cross section view of the lower portion of the gyratory crusher of the invention showing the eccentric assembly being removed and the hydraulic support installed in its working location. 
         FIG. 3  is a partial cross section view of a piston assembly showing the locations of the wear components. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a partial cross section view of the preferred embodiment of gyratory crusher  10  of the invention. It should be understood that except for the specific construction of lower portion  12  of crusher  10 , the crusher is constructed and operates similarly to prior art crushers. The basic structure of crusher  10  includes bowl or shell  14  shaped as a cone with its wider opening at the top, and head assembly  16  which is located on the axis of bowl  14 . Head assembly  16  is shaped as a cone and has its larger diameter at the lower end of bowl  14  so that together bowl  14  and head assembly  16  form crushing volume  18  which is larger at the top and smaller at the lower end. This configuration permits larger material  20  to be fed into the top of crusher  10 , and it falls to the bottom of bowl  14  as it is crushed into smaller pieces  22  and exits crusher  10 . Both bowl  14  and head assembly  16  have replaceable working surfaces. Bowl  14  has a liner  15 , called a “concave” in the industry, and head assembly  16  has a liner  17  referred to as a “mantle”. 
     Head assembly  16  is located by an eccentric assembly  28  which is rotated by ring gear  24  which is conventionally driven through drive gear  27  and drive shaft  26 . Eccentric assembly  28 , within which the lower portion of main shaft  34  is held, imparts to head assembly  16  an eccentric motion, essentially a gyration, for crusher  10  to function. The motion is imparted to head assembly  16  by eccentric assembly  28  that has an eccentric center volume, although eccentric assembly  28  is itself cylindrical and mounted in centered cylindrical support hole  31  within center hub  30 . Eccentric assembly  28  along with annular shell  32 , are part of the bottom support structure of crusher  10 . Eccentric assembly  28  rotates about center hole ( 31 ) and, as eccentric assembly  28  rotates, its eccentric center volume moves the bottom end of mainshaft  34  in an eccentric path imparting the gyratory motion to head assembly  16 . 
     Mainshaft  34  of head assembly  16  fits into and is attached to eccentric assembly  28 , and, at the top of crusher  10 , mainshaft  34  is located by bushings or bearings within spider  36 , which is the upper support member of crusher  10 . Eccentric assembly and mainshaft  34  are supported from below eccentric assembly  28  by hydraulic support assembly  49 , which is discussed with the following details of the present invention. 
       FIG. 2  is a partial cross section view of lower portion  12  of gyratory crusher  10  showing hydraulic assembly  49  which is comprised of cylindrical support  38  and piston assembly  46 . Eccentric assembly  28  is shown being removed from center hub  30  by being lifted straight up in direction A, while cylindrical support  38  remains installed in its working location. The lifting typically is performed by use of a crane after spider  36  and head assembly  16  ( FIG. 1 ) have previously been lifted out by the use of a crane. Mainshaft  34  has lifting hole  37  ( FIG. 1 ) formed in its uppermost region to facilitate its lifting. 
     Returning to  FIG. 2 , when eccentric assembly  28  is installed in cylindrical center hole  31  within center hub  30 , top support ring  40  of eccentric assembly  28  is supported by eccentric wear ring  42  at the top of center hub  30 . Eccentric wear ring  42  is integrated with outer eccentric bushing  44  and they both act as bearing surfaces for the rotation of eccentric assembly  28 . Ring gear  24  is also shown attached to eccentric assembly  28  by gear support  48 . 
       FIG. 2  also shows cylindrical support  38  in cross section with piston assembly  46  in place within cylindrical support  38 . The hydraulic supports of prior art gyratory crushers require removal from below. The present invention is constructed to permit cylindrical support  38  to be serviced and removed from the top of crusher  10 . 
     One feature that permits removal of cylindrical support  38  from above is that the cylindrical support includes circumferential upper lip  50 . Upper lip  50  is then supported by protruding support frame ledge  52  so that cylindrical support  38  can be lifted up out of its position in direction B. However, a further requirement of cylindrical support  38  is that its largest diameter, measured as the straight line distance between opposite points on the outer circumference of upper lip  50 , must be smaller than the diameter of center hole ( 31 ), which corresponds to the inner diameter of eccentric bushing  44 , measured as the straight line distance between opposite points on the inner surface of eccentric bushing  44 , to permit the passage of cylindrical support  38  through support hole  31  and out of crusher  10 . Put another way, assuming  FIG. 2  to be vertically situated, the largest horizontal dimension of the cylindrical support ( 38 ) must be less than and subsequently clear the smallest horizontal dimension within center hole ( 31 ). Of course, if the cylindrical support  38  can be thus removed from above the piston assembly, which fits within the cylindrical support, is also removable from above, with or without the cylindrical support being removed. 
     Such a configuration permits removal of cylindrical support  38  from crusher  10  without the previously required access from underneath such crushers. However, the present invention also dramatically reduces the need for removing the cylindrical support  38  because of the design of piston assembly  46 , which is the operational portion of hydraulic assembly  49 . In the prior art such removal of the hydraulic assemblies was required on a regular basis so that the several parts within a cylindrical support which were designed to be subject to wear, specifically piston bushings, could be replaced. However, in the present invention, all the parts within hydraulic assembly  49  which are normally designed to be subject to wear are now actually part of piston assembly  46 , so that it is usually necessary to remove only piston assembly  46  from crusher  10  to replace the wear parts. Under such circumstances, cylindrical support  38  may be left in its operating position. 
     As can be seen in  FIG. 2 , piston assembly  46  has an outside diameter that is significantly smaller than the inside diameter of eccentric bushing  44 . This size relationship makes it quite easy to lift piston assembly  46  up out of hydraulic support  38  and remove it from crusher  10  for service. 
       FIG. 3  is a partial cross section view of piston assembly  46  showing the locations of the wear components. Piston  60  is the major part upon which all the other components are mounted. The designed wear parts located on piston assembly  46  are upper piston bushing  64 , lower piston bushing  66 , hydraulic seal  70 , and piston wear ring  68 . Center wearing ring  62  is the contact and support element for mainshaft  34  and thus head assembly  16  ( FIG. 1 ), and upper piston bushing  64  and lower piston bushing  66 . Upper piston bushing  64  and lower piston bushing  66 , which in prior art designs were located on the cylindrical support, are the sliding contact surfaces between the outer diameter of piston assembly  46  and the inner diameter of cylindrical support  38 . Piston wearing ring  68  is configured to hold upper piston bushing  64  in place and also serves as a support for center wearing ring  62 . Hydraulic seal  70  is held in its location by retaining ring  72  and serves to prevent hydraulic fluid form leaking past piston assembly  46  instead of applying force to move it. Optionally, to facilitate easy installation of complete piston assembly ( 46 ) from above, piston assembly  46  can be constructed so that its upper piston bushing  64  has a larger diameter than the larger diameter of lower piston bushing ( 66 ) or piston seal ( 70 ). Typically, the differences will be comparatively small, and the diameter of upper piston bushing  64  be only about 1% to about 3% larger than the above referenced larger diameter. 
     As can be seen in  FIG. 3 , all of the designed wear parts are easily accessible when piston assembly  46  is removed from cylindrical support  38 , and that removal is easily performed from above crusher  10 . The invention thereby provides a gyratory crusher which can be serviced efficiently and, by avoiding the requirement for working underneath the crusher, can be serviced safely. 
     It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims.