Abstrict A gyratory crusher uses a new head nut attachment apparatus. The
gyratory crusher has a shell, a shaft disposed within the shell,
a mantle covering a portion of the shaft, a head nut located above
the mantle, and a sleeve between the head nut and the shaft. The
sleeve is maintained in position on the shaft by means of a tapered
contact surface between the sleeve and the shaft, and the head nut
is threaded onto the sleeve.
Claims What is claimed is:
1. An attachment apparatus in combination with a gyratory crusher
including a shaft and a mantle disposed about the shaft, the attachment
apparatus comprising: a sleeve disposed about the shaft defining
a contact surface between the sleeve and the shaft; and a head nut
threaded onto the sleeve; wherein the radius of the shaft increases
in an upward direction over at least part of the contact surface,
whereby the head nut retains the mantle with respect to the shaft
in at least one direction.
2. The attachment apparatus of claim 1 wherein the sleeve is made
of steel.
3. The attachment apparatus of claim 1 wherein the sleeve is fixed
to the shaft by means of a shrink fit.
4. The attachment apparatus of claim 1 wherein the sleeve is a
single piece ring.
5. The attachment apparatus of claim 4 wherein the sleeve has an
upper end, and a lower end, the upper end having an inner diameter
of 25.00 inches, and the lower end having an inner diameter of 24.95
inches.
6. The attachment apparatus of claim 1 wherein the contact surface
has a 1:315 taper from vertical.
7. The attachment apparatus of claim 1 wherein the head nut has
an inner diameter of about 26 inches and an outer diameter of about
31 inches.
8. The attachment apparatus of claim 1 wherein the contact surface
extends about eight inches.
9. The attachment apparatus of claim 1 wherein the sleeve is disposed
directly above the mantle.
10. An attachment apparatus in combination with a gyratory crusher
including a shaft and a mantle disposed about the shaft, the attachment
apparatus comprising: a sleeve disposed about the shaft; and a head
nut threaded onto the sleeve; wherein the sleeve is a continuous
ring, whereby the head nut prevents upward motion of the mantle.
11. The attachment apparatus of claim 10 further comprising: a
contact surface between the sleeve and the shaft; wherein the shaft
is tapered outwardly in an upward direction over at least part of
the contact surface.
12. The attachment apparatus of claim 10 wherein the sleeve is
made of steel.
13. The attachment apparatus of claim 10 wherein the sleeve is
releasably secured to the shaft by using a heat shrink method.
14. The attachment apparatus of claim 11 wherein the contact surface
has a 1:315 taper from vertical.
15. The attachment apparatus of claim 10 wherein the head nut has
an inner diameter of about 26 inches and an outer diameter of about
31 inches.
16. The attachment apparatus of claim 11 wherein the contact surface
extends about eight inches.
17. The attachment apparatus of claim 10 wherein the sleeve is
disposed at a position directly above the mantle.
18. A gyratory crusher, comprising: a shell; a shaft disposed within
the shell; a mantle covering a portion of the shaft; a head nut
located above the mantle; and a sleeve between the head nut and
the shaft; wherein the sleeve is maintained in position on the shaft
by means of a tapered contact surface between the sleeve and the
shaft.
19. The gyratory crusher of claim 18 wherein the sleeve is made
of steel.
20. The gyratory crusher of claim 18 wherein the sleeve is a continuous
ring of material.
21. The gyratory crusher of claim 18 wherein the head nut is threaded
onto the sleeve.
22. The gyratory crusher of claim 18 wherein the sleeve is affixed
to the shaft by means of a shrink fit.
23. The gyratory crusher of claim 18 wherein the shaft has a smooth
surface in the range of the contact surface.
24. The gyratory crusher of claim 18 wherein the contact surface
has a 1:315 taper from vertical.
25. The gyratory crusher of claim 18 wherein the head nut has an
inner diameter of about 26 inches and an outer diameter of about
31 inches.
26. The gyratory crusher of claim 18 wherein the contact surface
extends about eight inches.
Description FIELD OF THE INVENTION
This invention relates to rock crushing systems, such as conical
rock crushers or gyratory crushers. Specifically, this invention
elates to the main shaft assembly and head nut system.
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.
A head nut, attached to a sleeve disposed about the shaft is used
to retain the mantle in place. The head nut resists upward forces
from the mantle, which tends to move in an upward direction during
crusher operation. The head nut is also subject to wear from the
operation of the machine, as well as damage from impacts due to
the rocks being dumped into the machine from above. The head nut
is disposable, but the threads used to secure the head nut to the
shaft may become damaged as well. If the threads are stressed out
of shape due to operation, suffer fatigue failures such as cracking
of the threads, or are damaged due to impacts from falling material
on the head nut, repairs can be expensive. Repairing damaged threads
on the shaft may include removing the shaft from the machine to
be refurbished. The repair operation is costly both because of the
cost of reworking the shaft as well as the cost of machine down
time while the shaft is being repaired. Accordingly, the crushing
system is designed so that the shaft of the crusher is preserved
from being repaired in favor of other components which may be more
easily repaired or replaced, such as a sleeve.
A design that does not require threads on the shaft results in
a smooth shaft with a resultant lower incidence of failure. Sleeves
are sometimes used between the shaft and the head nut to avoid the
use of threads directly on the shaft, but the sleeves may require
complicated arrangements to be secured in a vertical direction with
respect to the shaft. Also, split sleeves that are sometimes used
require fasteners for installation. Preferably, the sleeve and head
nut are compact and replaceable in case of damage or maintenance
needs. The presence of additional fasteners on the sleeve or head
nut complicates assembly, removal, and maintenance.
Therefore, it would be advantageous to have a sleeve and head nut
arrangement that does not require threads on the shaft. Further,
there is a need for a head nut assembly that is self-tightening
in response to upward loads. Further still, there is a need for
a compact and easily replaceable sleeve and head nut arrangement
that does not require additional fasteners.
SUMMARY OF THE INVENTION
An exemplary embodiment relates to an attachment apparatus for
a gyratory crusher including a shaft and a mantle disposed about
the shaft. The attachment apparatus has a sleeve disposed about
the shaft defining a contact surface between the sleeve and the
shaft and a head nut threaded onto the sleeve. The radius of the
shaft increases in an upward direction over at least part of the
contact surface, whereby the head nut retains the mantle with respect
to the shaft in at least one direction.
Another embodiment relates to an attachment apparatus for a gyratory
crusher including a shaft and a mantle disposed about the shaft.
The attachment apparatus has a sleeve disposed about the shaft and
a head nut threaded onto the sleeve. The sleeve is a continuous
ring, whereby the head nut prevents upward motion of the mantle.
Still another embodiment relates to a gyratory crusher having a
shell, a shaft disposed within the shell, a mantle covering a portion
of the shaft, a head nut located above the mantle, and a sleeve
between the head nut and the shaft. The sleeve is maintained and
positioned on the shaft by means of a tapered contact surface between
the sleeve and the shaft.
A still further embodiment relates to a method of assembling or
repairing a gyratory crusher. This method includes heating a sleeve,
placing the sleeve over a shaft, cooling the sleeve to effect a
shrink fit arrangement on the shaft, and threading a head nut onto
the sleeve.
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 partial vertical cross-sectional view of a portion
of the gyratory crusher shaft.
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
10 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. 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. At an upper portion of the
head member 30 above the mantle 34 the shaft 20 has an outwardly
tapered segment 70. A sleeve 72 surrounds this outwardly tapered
segment 70 and a head nut 76 is threaded onto the sleeve 72. The
head nut 76 resists the upward force of the mantle 34 at an interface
80 between the two components.
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
includes an aperture 40 that receives a piston 41 and 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. Preferably
top shell 36 includes a recessed portion 92 for receiving a flange
94 of spider 46. Vertical positioning of shaft 20 with respect to
top shell 36 adjusts the relative position of concaves 62 with respect
to the mantle 34 of the head member 30 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.
Referring now to FIG. 2 the structure associated with the sleeve
72 and head nut 76 is shown. The mantle 34 has a tendency to move
upward during crusher operation. Thus, the head nut 76 is used to
retain the mantle 34 in place. In turn, the head nut must be secured
vertically with respect to the shaft 20. To accomplish this, a sleeve
72 is fixed to segment 70 of the shaft 20 and the head nut 76 is
attached to the sleeve 72. In a preferred embodiment, the head nut
76 is located about 40 inches from top of shaft 20 and is concentric
with the outside diameter of the sleeve 72.
In a preferred embodiment, the segment 70 begins at a point 73
located about 47 inches from top of the shaft 20. This shaft 20
increases in diameter in an upward direction in segment 70 a taper
of 1:315 from vertical. This is in contrast to the inward taper
of the shaft 20 below the upper segment 70 of 1:8.2. The inner diameter
of the sleeve 72 matches the 1:315 taper, and therefore is prevented
from moving in an upward direction by the increasing diameter. The
sleeve 72 is heated and shrunk onto the shaft 20 so no further fastening
means are required. The fit between the sleeve 72 and segment 70
is snug once the sleeve 72 is shrunk onto segment 70. Alternatively,
the sleeve 72 could have a V-shaped inner wall, fitting into a corresponding
shape on segment 70.
In a preferred embodiment, the sleeve 72 is a ring that at the
top portion has an inner diameter of 25.00 inches and an outer diameter
of 26.9 inches and at the bottom portion has an inner diameter of
24.95 inches and an outer diameter of 26.9 inches. This creates
the taper of 1:315 from vertical. The exterior of the sleeve 72
has sleeve threads 74. The threads 74 are American National-Right
Hand 0.5 inch pitch. The sleeve 72 is made of steel. The inner surface
of the sleeve 72 is a smooth fit with segment 70.
The head nut 76 retains the mantle 34 from moving upward during
crusher operation by direct resistance at an interface 80 between
the two components. The head nut 76 is made of steel and is threaded
onto the sleeve 72. Thus, the head nut 76 has threads 78 matching
the sleeve threads 74. The outer diameter of the head nut 76 is
31.3 inches in a preferred embodiment. Because the head nut 76 is
threaded onto the sleeve 72 rather than the shaft 20 the upward
load is transmitted through the threads to the sleeve 72 removing
stress concentrations from the shaft 20 because the shaft 20 does
not have threads. Additionally, if the upward load causes damage
to the sleeve threads 74 or head nut threads 78 or either one of
those members 72 or 76 those parts may be more easily repaired
or replaced than the shaft 20.
The sleeve 72 requires no fasteners for installation because it
is heat shrunk onto the shaft as one continuous ring. Additionally,
because of the reverse taper of segment 70 the sleeve 72 and head
nut 76 arrangement is self-tightening in responds to upward loads
from the mantle 34. Also, the reverse taper structure removes the
necessity of having additional structural members above the sleeve
72 or head nut 76 to retain those members in a stable vertical position
with respect to the shaft 20.
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 long-standing problems discussed
in the Background of the Invention section because the shrink fit
of the sleeve 72 onto segment 70 allows a smooth exterior surface
of the shaft 20 rather than the use of threads. The reverse taper
of segment 70 and sleeve 72 resists vertical displacement of the
sleeve 72 and head nut 76 in response to mantle 34 upward loads.
The sleeve 72 and head nut 76 are both easily replaceable, especially
because no fasteners are required to attach the sleeve 72 to the
shaft 20. Also because of the reverse taper, no further structure
is required to maintain the sleeve 72 in position with respect to
the shaft 20.
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 sleeve 72 and head nut 76 arrangement and method of installation.
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. |