Gyratory crusher main shaft and assembly

Abstract

A gyratory crusher main shaft assembly has a main shaft, an axially upper region of the main shaft including a tapered conical section with a protective sleeve friction fitted over the cone. To facilitate mounting and dismounting of the sleeve, at least one groove is indented within a radially external facing surface of the main shaft at the region of the cone to allow fluid to be introduced under pressure to the region between the sleeve and the cone.

Claims

1. A gyratory crusher main shaft of a crusher comprising: a shaft body having a radially outward facing external surface, and a first end and a second end; an axial region of the shaft body extending from the second end and being tapered relative to a longitudinal axis of the shaft body such that a cross sectional area of the shaft body at the tapered axial region decreases in a direction from the first end to the second end; a shaft sleeve mounted on the tapered axial region; and at least one groove indented at the external surface and positioned at the tapered axial region, the at least one groove being arranged to receive a pressurised fluid to facilitate mounting and dismounting of the shaft sleeve at the shaft body.

2. The main shaft as claimed in claim 1, further comprising a fluid inlet conduit extending axially from the second end and provided in fluid communication with the at least one groove to allow a fluid to be supplied to the at least one groove from the second end.

3. The main shaft as claimed in claim 2, wherein the fluid inlet conduit extends internally within the shaft body such that a part of the fluid inlet conduit extends radially outward to the at least one groove.

4. The main shaft as claimed in claim 3, wherein the at least one groove extends in a circumferential direction around the shaft body.

5. The main shaft as claimed in claim 4, wherein the at least one groove extends substantially or completely circumferentially around the shaft body.

6. The main shaft as claimed in claim 5, further comprising a plurality of grooves at the external surface.

7. The apparatus as claimed in claim 6, further comprising a first groove extending in a circumferential direction around the shaft body and a second groove extending in a circumferential direction around the shaft body, the first groove being separated axially from the second groove and coupled in fluid communication.

8. The main shaft as claimed in claim 7, wherein at least a part of the fluid inlet conduit is indented and extends axially at the external surface as a channel to couple the first and second grooves in fluid communication.

9. A gyratory crusher main shaft assembly for a crusher comprising: a shaft body having a radially outward facing external surface, and a first end and a second end, an axial region of the shaft body extending from the second end and being tapered relative to a longitudinal axis of the shaft body such that a cross sectional area of the shaft body at the tapered axial region decreases in a direction from the first end to the second end, a shaft sleeve mounted on the tapered axial region, and at least one groove indented at the external surface and positioned at the tapered axial region, the at least one groove being arranged to receive a pressurised fluid to facilitate mounting and dismounting of the sleeve at the shaft body; and a sleeve fitted over the tapered axial region, the sleeve having a tapered wall thickness, such that the wall thickness at a second end of the sleeve is greater than the wall thickness at a first end of the sleeve.

10. The assembly as claimed in claim 9, further comprising an end retainer releasably mounted at the second end of the shaft body and having a perimeter region extending radially outward beyond the external surface at the tapered region, the perimeter region positioned to radially overlap the sleeve at the second end of the sleeve to inhibit axial separation of the sleeve from the shaft body.

11. The assembly as claimed in claim 10, wherein the end retainer includes a recess extending circumferentially at the perimeter region to allow axial movement of the sleeve into the recess.

12. The assembly as claimed in claim 9, further comprising a fluid inlet conduit extending axially from the second end of the shaft body in fluid communication with the at least one groove to allow a fluid to be supplied to the at least one groove from the second end of the shaft body.

13. The assembly as claimed in claim 9, further comprising a fluid inlet conduit extending radially through the wall thickness of the sleeve in fluid communication with the at least one groove to allow a fluid to be supplied to the at least one groove through the sleeve.

14. A gyratory crusher comprising; a main shaft including a shaft body having a radially outward facing external surface, a first end for positioning at a lower region of the crusher and a second end for positioning at an upper region of the crusher relative to the first end, an axial region of the shaft body extending from the second end and being tapered relative to a longitudinal axis of the shaft body such that a cross sectional area of the shaft body at the tapered axial region decreases in a direction from the first end to the second end, the tapered axial region being configured to mount a shaft sleeve; a sleeve fitted over the tapered axial region, the sleeve having a tapered wall thickness such that a wall thickness at a second upper end of the sleeve is greater than a wall thickness at a first lower end of the sleeve; and at least one groove indented at the external surface and positioned at the tapered axial region, the at least one groove being arranged to receive a pressurised fluid to facilitate mounting and dismounting of the sleeve at the shaft body.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) A specific implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:

(2) FIG. 1 is a cross sectional side view of a gyratory crusher having a main shaft supported at its upper end by a top bearing assembly and having a protective sleeve mounted about the upper end of the main shaft according to a specific implementation of the present invention;

(3) FIG. 2 is a perspective partial cross section through the upper end of the main shaft and sleeve assembly;

(4) FIG. 3 is a perspective partial cross section of the shaft upper end of FIG. 2 with the protective sleeve removed;

(5) FIG. 4 is a further external perspective view of the tapered axial section of the main shaft upper end of FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

(6) Referring to FIG. 1, a crusher comprises a frame 100 having an upper frame 101 and a lower frame 102. A crushing head 103 is mounted upon an elongate shaft 107 having a longitudinal axis 115. A first (inner) crushing shell 105 is fixably mounted on crushing head 103 and a second (outer) crushing shell 106 is fixably mounted at upper frame 101. A crushing zone 104 is formed between the opposed crushing shells 105, 106. A discharge zone 109 is positioned immediately below crushing zone 104 and is defined, in part, by lower frame 102.

(7) A drive (not shown) is coupled to main shaft 107 via a drive shaft 108 and suitable gearing 116 so as to rotate shaft 107 eccentrically about a longitudinal axis 126 of the crusher and to cause head 103 to perform a gyratory pendulum movement and crush material introduced into crushing chamber 104. A first (axial upper) end region 113 of shaft 107 is maintained in a rotatable position by a top-end bearing assembly 112 positioned intermediate between main shaft 107 and a central boss 117. Similarly, a second (axial bottom) end 118 of shaft 107 is supported by a bottom-end bearing assembly 119. Upper frame 101 is divided into an upper frame part (commonly termed a topshell 111) mounted upon lower frame part 102 (commonly termed a bottom shell), and a spider assembly 114 having arms 110 that extend from topshell 111 and represents an upper portion of the crusher.

(8) Upper end region 113 comprises a radial taper that defines an upper conical region of main shaft 107. The conical region 113 is tapered so as to decrease in cross sectional area in a direction from shaft second (lower) end 118 to an upper end surface 123 positioned uppermost within the crusher. To avoid excessive wear of the conical region 113, by contact with bearing assembly 112, a substantially cylindrical wear sleeve 124 is mounted over and about region 113. Sleeve 124 is held in position at region 113 by an interference or friction fit and is provided in close touching contact over an axial length of both sleeve 124 and region 113. Accordingly, sleeve 124 is positioned radially intermediate bearing assembly 112 and an outer surface of region 113 to absorb the radial and axial loading forces resultant from the crushing action of the gyratory pendulum movement.

(9) To facilitate mounting and dismounting of sleeve 124 at shaft region 113, shaft 107 is configured to enable a fluid to be introduced into the contact region between the sleeve 124 and shaft region 113. In particular, a fluid supply conduit 120 extends axially and radially along shaft 107 (within region 113) from end surface 123 to the contact region between sleeve 124 and region 113. A channel (alternatively termed a groove) 121 is indented within the external facing surface of shaft 107 at region 113 and is provided in fluid communication with conduit 120.

(10) Referring to FIGS. 2 to 4 tapered region 113 comprises a lowermost end 300 and an uppermost end 301. The radial taper is uniform along the axial length between ends 300, 301 such that a cross sectional area decreases from lower end 300 to upper end 301 at a uniform rate to define a frusto-conical region (113) of main shaft 107. Sleeve 124 comprises a first (lower) end 216 for mating at the end 300 of region 113 and a second (upper) end 215 for positioning at uppermost end 301 substantially coplanar with shaft end surface 123. Sleeve 124 comprises a radially inward facing surface 201 and a radially outward facing surface 202 with a substantially cylindrical wall 203 defined between surfaces 201, 202. Wall 203 is tapered so as to decrease in radial thickness from uppermost end 215 to lowermost end 216. In particular, external surface 202 is substantially cylindrical whilst internal surface 201 comprises a conical shape profile corresponding to the conical shape profile of main shaft region 113. Region A, illustrated in FIG. 2, corresponds to a mid-axial length position as defined by the cross sectional area of wall 203 (in a plane extending along axis 115) such that the cross sectional area axially above region A is equal to the cross sectional area axially below region A. Sleeve 124 and in particular radially inward facing surface 201 is mated in close fitting contact with the external facing surface 200 of main shaft region 113 between respective lower (216, 300) and upper (215, 301) ends.

(11) Sleeve lower end 216 comprises a chamfer region 207 of decreasing wall thickness such that very a lowermost end region of sleeve 124 is chamfered to sit close to a radius section of main shaft region 113 below region end 300.

(12) A disc-like retainer 125 is releasably mounted over shaft end surface 123 during mounting and dismounting of sleeve 124 at main shaft region 113. Retainer 125 comprises a suitable bore 122 aligned coaxially with an end region of conduit 120 to allow fluid to be introduced through retainer 125 to groove 121 via conduit 120. Retaining disc 125 comprises a plurality of perimeter bores 214 distributed circumferentially around retainer 125 immediately inside of a perimeter 209. Bores 214 are configured to receive attachment bolts (not shown) received within corresponding bores (not shown) extending axially from sleeve upper end 215 so as to lock retainer 125 to sleeve 124 during mounting and dismounting procedures. Retainer 125 further comprises a plurality of additional bores 213 positioned radially inside perimeter bores 214 that are configured to receive attachment bolts (not shown) to secure retainer 125 to main shaft region 113. In particular, an underside surface 211 of retainer 125 is positioned in contact and aligned substantially coplanar with the shaft end surface 123. In this orientation, an upward facing retainer surface 212 is orientated away from main shaft 107. An annular recess 210 extends circumferentially around retainer perimeter 209 and is indented in surface 211 so as to create a small axially and radially extending annular gap region immediately axially above the annular sleeve end 215.

(13) Accordingly, during a sleeve dismounting operation, the sleeve attachment bolts (not shown) are removed. Sleeve 124 is capable of sliding axially into the gap region defined by recess 210 to contact the underside surface 211 (at the recess 210) when fluid pressure is applied. In an alternative mounting operation, retainer 125 is inverted such that disc surface 212 is mated against sleeve end 215 and main shaft end surface 123 to force sleeve 124 axially over and about region 113 as the attachment bolts (not shown) are tightened.

(14) Fluid supply conduit 120 comprises an axial section 204 extending downwardly from end surface 123. A lowermost end 206 of axial section 204 is terminated by a radially extending section 205 that terminates at shaft external facing surface 200. A radially outermost end of the conduit section 205 is provided in fluid communication with an axially upper groove 121a that extends circumferentially around shaft region 113.

(15) According to the specific implementation, conical region 113 further comprises a second circumferentially extending groove 121b axially separated from the first upper groove 121a by a distance approximately half the axial length of region 113 and sleeve 124. Additionally, each groove 121a, 121b is spaced axially from region A by an equal axial distance. Grooves 121a and 121b also extend the full 360° circumference of shaft surface 200. An interconnecting fluid flow channel 208 extends axially from upper groove 121a to lower groove 121b to provide fluid communication between the two grooves 121a, 121b.

(16) According to further specific implementations, region 113 may comprise a plurality of interconnecting fluid flow channels 208 distributed circumferentially around surface 200. According to yet further embodiments, region 113 may comprise a single circumferentially extending groove optionally in the form of at least one spiral or helix. According to a further embodiment, external facing surface 200 may comprise a network of grooves orientated and extending axially parallel or transverse to axis 115 and/or in a circumferential direction entirely or partly around the conical surface 200.

(17) The subject invention is compatible for use with conventional fluid supply systems (comprising reservoirs, pumps, conduits, seals etc.) coupled to bore 122 via suitable enclosures or conduits. Accordingly, a fluid is capable of being delivered to grooves 121a, 121b via supply conduits 120, 208 to lubricate the interface between shaft surface 200 and sleeve surface 201. Such an arrangement facilitates both a slide mounting of sleeve 124 and imparts a radial expansion force (to sleeve 124) to promote sleeve demounting.

(18) According to further specific embodiments, shaft region 113 may be devoid of conduit 120 such that sleeve 124 comprises a conduit bore extending through sleeve wall 203 in fluid communication with grooves 121a, 121b and/or channel 208.