Abstract:
A bearing retainer apparatus for a gyratory crusher is comprised of a bearing having a ball, a shaft disposed within the ball, and a plate secured to the shaft. Further, a method of assembling a bearing retainer system for a gyratory crusher includes attaching a bearing retainer plate onto the shaft of the crusher using bearing retainer bolts such that the bearing is clamped onto the shaft.

Description:
FIELD OF THE INVENTION 
     The present invention relates to rock crushing systems, such as conical rock crushers or gyratory crushers. More specifically, the present invention relates to a mainshaft bearing retainer for rock crushers. 
     BACKGROUND OF THE INVENTION 
     Gyratory rock crushers generally have a downwardly expanding central conical member which rotates or gyrates within an outer upwardly expanding frustroconically shaped member typically called a shell. The shell can be comprised of two or more pieces, e.g., a top shell and a bottom shell. The central conical member generally has a wearing cover or a liner called a mantle. A spider assembly rests on the top shell, forming the top of the support structure for the machine. 
     A shaft extends vertically through the rock crusher. This shaft is supported by a bearing in the spider assembly. The central portion of the shaft tapers inwardly in an upward direction to form the central conical crushing member. This portion of the shaft supports the mantle, which moves with the shaft to effect the crushing operation. 
     The spider assembly is designed to support the shaft while allowing gyratory movement during operation of the machine. Additionally, the vertical position of the shaft is controlled by a piston arrangement in the spider. The piston is slidably disposed within the spider. A bearing is disposed within the piston, and supports the shaft while allowing gyratory motion. The bearing has a hemispherical ball disposed in a socket, lubricated by oil or grease. A mechanical attachment system is required to clamp the ball to the shaft. 
     In previous designs, the ball has been secured to the shaft using a fastener, such as a nut. The nut is threaded onto the shaft above the ball, which in turn has a hydraulic system used to press the ball onto the shaft. In this type of arrangement, the shaft must extend through the ball to allow the nut to be threaded above the ball. The nut is retained by a bracket system bolted to the top of the shaft. 
     The conventional mechanical attachment systems are difficult and costly to assemble, repair, and replace because of the complexity of the arrangement. As described above, conventional systems use a hydraulic system to press the ball onto the shaft during assembly and a retainer system to prevent the nut from loosening on the shaft during operation. Further, the threaded shaft is subject to high stress in the area of its threads due to the weight of the shaft and the gyratory motion during crusher operation. Repairs to the shaft can be costly due to the expense of the shaft as well as the expense of the down time necessary to make repairs. 
     In contrast to conventional bearing retainer systems, it would be advantageous to have a bearing retainer arrangement that may be easily assembled, removed, and replaced. Further, there is a need for a bearing retainer system that does not require threads on the exterior of the shaft of the gyratory crusher. Further still, there is a need for a bearing retainer system that does not require a hydraulic system to assemble the ball and the shaft. 
     SUMMARY OF THE INVENTION 
     An exemplary embodiment relates to a bearing retainer apparatus. The bearing retainer apparatus is for a gyratory crusher. The bearing retainer apparatus includes a ball, a shaft disposed within the ball, and a plate configured to prevent the ball from moving upward on the shaft. The plate is secured to the shaft. 
     Another embodiment relates to a gyratory crusher including a shell, a shaft disposed within the shell, and a spider coupled to the shell. A bearing having a ball is disposed within the spider, and a bearing retainer plate clamps the ball to the shaft. 
     A still further embodiment relates to a method of assembling a bearing retainer system for a gyratory crusher having a shaft and a ball. The method includes steps of providing a bearing retainer plate, providing a plurality of bearing retainer bolts, placing the ball on the shaft, and attaching the plate to the shaft with the bolts. The ball is clamped to the shaft. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and: 
     FIG. 1 is a vertical cross-sectional view of the gyratory crusher; and 
     FIG. 2 is a more detailed cross-sectional view of the bearing and retainer of a gyratory crusher. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, a gyratory crusher  10  can be utilized to crush rock, ore, minerals, waste, or other material. Gyratory crusher is assembled on a cast steel base or bottom shell  12  having a central hub  14 . Central hub  14  is provided with a vertical bore  18  adapted to receive a cylindrical support shaft  20  and eccentric  24 . This shaft  20  varies in cross section, but extends through the machine into the spider  46 . Drive housing  13  extends outwardly from hub  14  to enclose a drive mechanism  22 . Drive mechanism  22  causes rotation of an eccentric  24  which directs the gyratory motion of the shaft  20 . 
     A head assembly  26 , which is part of the shaft  20 , includes a head member  30  which is covered by a mantle  34 . Mantle  34  provides one of the crushing surfaces of crusher  10 . 
     A top shell  36  projects upwardly from bottom shell  12  and is covered by a spider assembly including a spider  46 . Alternatively, top shell  36  and bottom shell  12  can be a single piece component. Spider  46  receives an end  42  of shaft  20 . 
     Top shell  36  is protected from wear by several rows of concaves  62 . These concaves  62  provide the crushing surface opposing mantle  34 . Spider  46  can be attached or rest upon top shell  36 . Vertical positioning of shaft  20  with respect to top shell  36  adjusts the relative position of the mantle  34  of the head member  26  with respect to concaves  62  thereby adjusting the size of the crushed material exiting crusher  10 . 
     Material to be crushed is supplied through spider  46  which includes openings (not shown) for entry of the material into crushing cavity  50 . A liquid flush apparatus (not shown) may be provided for spraying a liquid such as water toward the crusher cavity  50 . 
     The spider  46  is comprised of spider arms  52  radially extending outward from the center to a spider rim (not shown). A spider cap  54  sits on the top center of the spider  46 . Each of the spider arms  52  is protected from falling material by a spider arm guard  56 . The spider rim is protected by a rim liner (not shown), also known as a hopper liner. 
     Shaft  20  is supported by a bearing  80  within spider  46 . The bearing  80  is disposed within a piston  82  that travels vertically within spider  46  to adjust the vertical positioning of shaft  20 . The piston  82  is moved by means of a hydraulic system including a hydraulic fluid inlet  84 , and a hydraulic fluid ring  86  that is filled to move piston  82  upward. A bearing retainer plate  92  is used to clamp a bearing ball  81  to the shaft  20 . 
     The bearing ball  81  is disposed within socket  90 . It has a hemispherical structure designed to receive top end  42  of shaft  20 . The ball  81  has a radius of about thirteen inches and is lubricated by oil injected between ball  81  and socket  90 . An upper end of the ball has a longer horizontal dimension D than a lower end thereof. 
     Referring now to FIG. 2, shaft  20  is supported within bearing  80  by a bearing retainer plate  92  and bearing retainer bolts  94 . Bearing retainer plate  92  is made of steel, has a diameter of about twenty-one inches and is about two and one-half inches thick. Ball  81  has a flat surface on top, upon which bearing retainer plate  92  may rest. Bearing retainer plate  92  is attached to shaft  20  by bearing retainer bolts  94 . 
     In a preferred embodiment, a bearing lip  98  extends partially into the space between shaft  20  and bearing retainer plate  92 . The lip  98  has a thickness of about one inch and extends about one-half inch inward from the perimeter of shaft  20 . Thus, in a preferred embodiment, the lip  98  has an inner diameter of about fourteen inches. Because the diameter of the bearing retainer plate  92  is greater than that of the inner diameter of the ball  81 , the plate  92  overlays ball  81  with an annular contact surface area of about 190 square inches, having an inner diameter of fourteen inches and an outer diameter of twenty-one inches. 
     In the preferred embodiment, the bearing retainer bolts  94  are M30×120 mm steel bolts. There are preferably  10  bearing retainer bolts  94  clamping the plate  92  to the shaft  20 . There are no threads on the shaft  20  at the interface  96  between ball  81  and shaft  20 . Threads are not necessary because shaft  20  is supported by bearing retainer bolts  94 . 
     The bearing retainer plate system precludes the need for a nut threaded on shaft  20  to secure ball  81  to shaft  20 . Because no nut is used, no hydraulic system is necessary to apply assembly loads between ball  81  and shaft  20 . Instead, a clamping load and assembly load are provided by bolts  94 . The lack of threads on the exterior of the shaft  20  reduces possible stresses on and resultant damage to the shaft  20 . 
     Bearing  80  must support shaft  20  while allowing gyratory motion. These loads can be substantial as shaft  20  weighs twenty-four tons in a preferred embodiment. The bolts  94  and bearing retainer plate  92  can be designed to support that load. 
     Additionally, bearing retainer bolts  94  resist loads due to the gyratory motion of shaft  20 . Shaft  20  is generally constructed of steel, which may be threaded to allow bolts  94  to be attached. To support the loads of shaft  20  during crusher  10  operation, the bolts  94  are threaded two inches into shaft  20  in the preferred embodiment. 
     In the preferred embodiment, bearing retainer plate  92  is easily removed from shaft  20  and bearing  80  for repair and replacement. This is an advantage over systems using a large nut to clamp ball  81  onto shaft  20  because systems using a large nut have an additional hydraulic system as well as an apparatus required to prevent nut from loosening during operation. Therefore, the present bearing retainer plate device is superior to conventional designs with respect to ease of installation and maintenance. 
     The gyratory crusher  10  operates as follows. When the drive mechanism  22  is driven by any appropriate means, it transmits power to the eccentric  24 . The eccentric  24  causes the gyration of the head assembly  26 , resulting in the crushing of the material in the crushing chamber  50 . The phantom lines flanking the mantle and center axis on FIG. 1 indicate the range of gyratory motion. 
     The above arrangement solves the longstanding problems discussed in the Background of the Invention section because the exterior of the shaft  20  does not require threads that increase stresses on the shaft  20  and are susceptible to breakage and wear. Additionally, the low cost and simplicity of the bearing retainer plate system is superior to the complicated retaining systems of the prior art. Finally, the bearing retainer plate  92  and bolts  94  may be more easily removed and installed than prior systems. This allows for more efficient maintenance and installation which results in lower costs. 
     While several embodiments of the invention have been described, it should be apparent to those skilled in the art that what has been described is considered at present to be the preferred embodiments of a bearing retainer system. However, in accordance with the patent statutes, changes may be made in the design without actually departing from the true spirit and scope of this invention. The following claims are intended to cover all such changes and modifications which fall within the true spirit and scope of this invention.