Abstrict A gyratory crusher includes a bowl assembly with a concave crushing
surface and a crusher head of conical shape which extends into the
concave portion of the bowl assembly. A central crusher axis extends
centrally through the bowl assembly. The crusher head is mounted
with a central head axis at an angular deviation with respect to
the central crusher axis to intersect the crusher axis at an apex.
Crushing action is obtained by driving the crusher head to gyrate
the angular offset of its central axis about the central crusher
axis. The gyratory crusher has an adjustable stroke of gyration.
Adjustability of the stroke is obtained by controllably varying
the amount of angular deviation by which the crusher head gyrates
about the central crusher axis. The amount of angular deviation
is controlled by an eccentric support bearing which gyrates a guide
shaft of the crusher head about the crusher axis and which is adjustably
mounted to move toward and away from the apex of gyration without
also changing the position of the crusher head with respect to the
apex.
Claims What is claimed is:
1. A method of crushing materials with a gyratory crusher, the
gyratory crusher including a crusher bowl centered on a central
vertical crusher axis, a crusher head disposed below the crusher
bowl, and a gyratory drive including a bearing for retaining the
crusher head at a predetermined angle of deviation with respect
to the central vertical crusher axis for gyratory motion of the
crusher head at a defined angle of deviation about the central vertical
crusher axis, the method comprising the preparatory steps of:
adjusting the position of the bearing within the gyratory crusher
and thereby adjusting the defined angle of deviation of the crusher
head and a stroke length of gyration of the crusher head of the
gyratory crusher; and
verifying that a minimum desirable opening exists at a closed side
between the crusher bowl and the crusher head, and adjusting the
opening at the closed side to a minimum desired open setting if
the minimum desirable opening does not exist after adjusting the
stroke length of gyration of the gyratory crusher.
2. The method of crushing materials according to claim 1 wherein
adjusting the position of the bearing and the stroke length comprises
adjusting the height of an eccentric drive piston supporting the
bearing along the central vertical crusher axis and the bearing
along the length of a guide shaft extending downward from a crusher
head, thereby changing the defined angle of deviation of the crusher
head with respect to the central vertical crusher axis.
3. A gyratory crusher comprising:
a bowl assembly disposed centered on a central crusher axis, the
bowl assembly having a concave crushing surface;
a crusher head assembly including a conical crusher head centered
on a crusher head axis and disposed toward the concave crushing
surface of the bowl assembly;
means for supporting the crusher head assembly generally along
the central crusher axis for tilting movement of the crusher head
with respect to an apex along the central crusher axis to support
gyrational movement of the crusher head toward the bowl assembly;
drive means including an eccentric support bearing engaging the
crusher head and means for supporting the eccentric support bearing
at a predetermined distance of eccentricity from the central crusher
axis for generating an angular deviation of the crusher head axis
with respect to the central crusher axis and for driving the crusher
head in a gyrational orbit about the apex at an angular deviation
to generate a gyrating stroke of the crusher head with respect to
the bowl assembly; and
means for controllably changing the angular deviation of the crusher
head axis with respect to the central crusher axis.
4. The gyratory crusher according to claim 1 wherein the means
for supporting the eccentric support bearing comprises a drive piston,
and the crusher head comprises a guide shaft extending from the
crusher head into the drive piston, the guide shaft of the crusher
head rotatably engaging the eccentric support bearing, the eccentric
support bearing rotatably retaining the guide shaft at the predetermined
distance with respect to the central crusher axis, and wherein the
means for controllably changing the angular deviation of the crusher
head axis comprises means for vertically moving the drive piston
with respect to the apex.
5. The gyratory crusher according to claim 1 wherein the drive
means comprises a drive piston centered on the central crusher axis,
the drive piston being supported for rotation about the central
crusher axis, the means for supporting the eccentric support bearing
being a support cavity disposed within the drive piston, the support
cavity being radially offset from the central crusher axis by a
predetermined distance corresponding to the distance of eccentricity,
and wherein the means for controllably changing the angular deviation
of the crusher head axis comprises means for vertically adjusting
the position of the drive piston with respect to the apex.
6. The gyratory crusher according to claim 5 wherein the crusher
head comprises a guide shaft extending from the crusher head centrally
through the eccentric support bearing into the drive piston, the
guide shaft being journalled for rotation within the eccentric support
bearing, and wherein the eccentric support bearing is mounted for
movement relative to the drive piston perpendicularly to an axis
of rotation of the guide shaft with respect to the support bearing.
7. The gyratory crusher according to claim 6 wherein the bearing
support cavity is a spherical cavity and the support bearing has
an external spherical shape and a bore extending through the center
of the spherical shape, the bore adapted to rotationally support
the guide shaft.
8. The gyratory crusher according to claim 7 wherein the means
for vertically adjusting the position of the drive piston with respect
to the apex comprises a drive link coupled to the drive piston and
actuator means for raising and lowering the drive link with respect
to the apex to thereby adjust the position of the drive piston accordingly.
9. A gyratory crusher comprising:
a crusher frame assembly having a central vertical axis and including
a support structure for supporting a crusher head along the central
vertical axis;
a crusher head supported by the frame assembly along the central
vertical axis, the crusher head including a guide shaft extending
downward from the crusher head into the frame assembly;
an eccentric drive member mounted within the frame assembly concentric
with the central vertical axis, the frame assembly including bearings
for rotatably supporting the eccentric drive member to rotate on
the central vertical axis, the eccentric drive member including
an eccentric bearing having a bore displaced from the central vertical
axis for retaining the guide shaft of the crusher head at an angle
of deviation with respect to the central vertical axis;
a drive mechanism engaging the eccentric drive member to rotate
the eccentric drive member and to gyrate the guide shaft with respect
to the central vertical axis; and
a positioning mechanism coupled to the eccentric drive member,
the positioning mechanism supported with respect to the crusher
frame assembly and including a drive link coupled to the eccentric
drive member to reposition the eccentric bearing and change the
angle of deviation of the guide shaft with respect to the central
vertical axis, whereby a stroke length of gyration of the crusher
head changes.
10. The gyratory crusher according to claim 9 wherein the eccentric
bearing is mounted for movement in a plane of the central vertical
axis and an axis of deviation of the guide shaft disposed within
the bore of the eccentric bearing.
11. The gyratory crusher according to claim 9 wherein the crusher
frame assembly comprises a support cylinder having a cylindrical
chamber centered on the central vertical axis, the eccentric drive
member comprises an eccentric drive piston disposed within the cylindrical
chamber for vertical movement, and the drive link of the positioning
mechanism is a vertical drive link coupled to move the eccentric
drive piston through a range of vertical positions, thereby changing
the angle of deviation of the guide shaft with respect to the central
vertical axis.
12. The gyratory crusher according to claim 11 wherein the eccentric
drive member includes a spherical socket for supporting the eccentric
bearing and the eccentric bearing is externally of an essentially
spherical shape with the bore extending axially through the eccentric
bearing.
13. The gyratory crusher according to claim 9 comprising a bowl
assembly disposed centered on the vertical crusher axis above the
crusher head, the gyratory crusher further comprising an adjustment
mechanism for adjusting the vertical height between the bowl assembly
and the crusher head to a desired closed side setting between the
crusher head and the bowl assembly.
14. The gyratory crusher according to claim 13 wherein the bowl
assembly comprises a crusher bowl and a bowl flange supporting the
crusher bowl with respect to the crusher frame assembly, and the
adjustment mechanism for adjusting the vertical height comprises
complementary helical threads on the bowl flange and on the crusher
bowl for adjusting the crusher bowl vertically with respect to the
crusher frame assembly.
15. The gyratory crusher according to claim 14 wherein the crusher
frame assembly comprises a support cylinder having a cylindrical
chamber centered on the central vertical axis, the eccentric drive
member comprises an eccentric drive piston disposed within the cylindrical
chamber for vertical movement, and the drive link of the positioning
mechanism is a vertical drive link coupled to move the eccentric
drive piston through a range of vertical positions, thereby changing
the angle of deviation of the guide shaft with respect to the central
vertical axis.
16. The gyratory crusher according to claim 13 wherein the eccentric
drive member comprises a spherical socket for supporting the eccentric
bearing and the eccentric bearing is of complementary spherical
shape, the bore of the eccentric bearing extending diametrically
through the eccentric bearing.
Description BACKGROUND OF THE INVENTION
The invention relates to gyratory crushers and particularly to
the gyratory motion mechanism of gyratory crushers.
The invention may be best understood in consideration of generally
understood operating characteristics of gyratory crushers. Gyratory
crushers or cone crushers are those which support a cone-shaped
crushing head capable of undergoing a gyrating motion centered generally
about a vertical central axis through the crusher. The gyrating
motion of the crushing head performs a crushing action on material
which enters a space between the head and an inner surface of a
concave or bowl-shaped stationary member. The bowl-shaped member
is disposed in an inverted position generally over the cone-shaped
crushing head. The bowl-shaped member is centered on the axis through
the crusher and has a central opening through which materials, such
as rock, ore, coal or the like are fed into the space between the
crushing head and the stationary, bowl-shaped member. The action
of the crusher typically distributes the materials annularly about
the centrally disposed conical shape of the crushing head. The materials
typical move by gravity into the annular space between the inner
wall of the stationary bowl member and the outer, cone-like surface
of the crushing head. The annular space between the bowl member
and the crushing head is also referred to as the crushing chamber.
The gyration of the crushing head causes the space at any specific
radial position of the crusher to cyclically increase and decrease
in width. The cyclic, relative motion of the two members comminutes
the materials as they are drawn by gravity though the annular, downward
sloping space to be discharged at the base of the crushing chamber.
Cone crushers are generally chosen to be optimally suited for specific
operating conditions and materials. The shape of the crushing chamber,
the angle of the conical head, the stroke (the difference between
the extremes of gyratory movement of the crushing head), and the
rotational speed of the gyratory drive are factors which are typically
considered in the selection of a crusher. Selection of a crusher
with optimum specifications including its size is often based on
prior experience with the materials to be comminuted. For example,
the hardness of rock or ore may limit the amount of reduction that
can be achieved in a single path. Consequently, hard rock may require
a stroke length on the short end of a range of typically specified
gyration strokes. Such relatively short stroke may limit the material
throughput rate or capacity of the crusher. On the other hand, a
comparatively easier to crush or softer material or rock may permit
a greater reduction during a single pass, hence a relatively longer
stroke of the crusher may be specified. The relatively long stroke
may, in general, also permit a greater material throughput.
For many commercial crushing applications, however, gyratory crushing
plants are intended for use at many different locations. For example,
road construction projects often require crushing operations at
a number of successively accessed quarries. Each location may provide
materials of different hardness. For crushers intended to produce
under such variable conditions, it would generally not be possible
to preselect operating specifications of the crusher to optimize
the crusher for any particular source material. Instead, it appears
desirable to have available a crusher which can be adjusted to work
optimally with materials without much concern as to hardness or
crushability. An ideal crusher would permit an operator to optimize
crusher throughput and product quality at each new site, as for
example by making sample runs and by fine tuning of certain adjustable
operating parameters of the crusher.
For any given crusher size and type, the closed side setting (CSS)
which is the least gap between the crusher head and the bowl, may
not be less than a certain minimum setting at which the crusher
begins to be overloaded. The CSS is typically adjustable by raising
or lowering the bowl or stationary member with respect to the crusher
head. According to some known crusher makes the crushing head may
be raised or lowered to establish the CSS. The rotational speed
of the crusher head may, of course, be changed. However, for any
one crusher the throughput or production capacity of the crusher
may not increase with an increase in the crusher speed. The production
capacity of the crusher may even decrease slightly with a speed
up in rotational speed.
The length of the stroke of the crusher, namely the difference
between a maximum opening and a minimum opening at a given section
through the space between the head and the bowl, does have an effect
on the throughput of the crusher. The stroke length is typically
established by the design of the crusher components, such as the
amount of eccentricity in a camming member or sleeve which transforms
rotational motion of a drive member into the desirable, gyrational
motion of the crusher head. A cone crusher of a certain size when
equipped with an eccentric member with increased eccentricity with
respect to that of an original eccentric member, may show a marked
increase in production capacity. A corresponding increase in the
drive power or the rotational speed of the drive member may increase
the power input to the crusher to accommodate the increased crushing
action for a correspondingly improved production capacity. However,
a comparatively longer stroke may not be optimally suited for relatively
hard materials which require greater crushing force. Thus, typically
a compromise stroke length is chosen which may not permit an ideal
production rate in certain crushing operations.
SUMMARY OF THE INVENTION
From the foregoing it appears desirable to equip a gyrational crusher
with an arrangement for adjusting the length of the crusher stroke.
An ability to adjust the stroke of the crusher permits the operation
of the crusher to become optimized to crush materials of various
hardness or resistance to crushing.
In accordance with the invention, a gyratory crusher includes a
stationary bowl assembly disposed centered on a crusher axis, and
a crusher head assembly having a conical crusher head disposed for
gyratory motion against a concave crushing liner of the bowl assembly.
A gyration support assembly supports the crusher head for gyrational
movement with respect to the bowl assembly. A gyration drive assembly
includes an eccentric drive arrangement for driving the crusher
head in a gyrational orbit about an apex on and at an angular deviation
with respect to the central crusher axis to generate gyrating stroke
of the crusher head with respect to the bowl assembly. A stroke
control assembly includes a provision for changing the angular deviation
of the crusher head to change the stroke of the crusher head with
respect to the bowl assembly.
Various advantages of the invention and features of a preferred
embodiment of the invention are set forth in a detailed description
below.
BRIEF DESCRIPTION OF THE DRAWING
The Detailed Description including the description of a preferred
structure as embodying features of the invention will be best understood
when read in reference to the accompanying figures of drawing wherein:
FIG. 1 is a broken vertical section through a gyratory crusher,
showing major elements of the crusher as an embodiment of the invention;
FIG. 2 is a simplified sectional view of a gyratory crusher illustrating
schematically a mechanism for adjusting the stroke length of the
crusher head, and showing the crusher head adjusted for a relatively
long gyrational stroke excursion; and
FIG. 3 is a simplified sectional view of a gyratory crusher as
in FIG. 2 wherein the crusher head is set for a relatively short
gyrational stroke excursion.
DETAILED DESCRIPTION OF THE INVENTION
The Crusher Structure
In reference to FIG. 1 a gyratory crusher 10 includes broadly
a frame assembly 12 a stationary bowl assembly 14 supported by
an upper rim 16 of the frame assembly, a crusher head assembly 18
disposed below the bowl assembly 14 and a crusher drive assembly
20.
The frame assembly 12 substantially defines outer lateral dimensions
of the crusher 10 and provides support for various structural and
functional elements of the crusher 10. The frame assembly 12 is
made up of distinguishable structural frame elements which are preferably
welded to form a unitary frame structure and impart structural integrity
to the frame assembly. A cylindrical outer shell 25 defines generally
the outer dimension of the crusher 10. A number of spider support
ribs 26 are vertically oriented plates 26 which extend radially
between the outer shell 25 and an inner head support frame 27. The
support ribs 26 are generally evenly spaced along the inside of
the outer shell 25. The head support frame 27 is a cylindrical member
which is disposed concentrically within the outer shell 25. A central
vertical axis 30 through the outer shell 25 is common to a central
axis of the inner head support frame 27 and also coincides with
and constitutes a central axis 30 of the crusher 10.
An annular gap 32 defined by an inner surface 33 of the outer shell
25 and an outer surface 34 of the head support frame 27 provides
a discharge region for crushed materials 35 falling from the crusher
10 as indicated by an arrow 35. It may be preferred to provide replaceable
inner liners (not shown) adjacent each of the respective surfaces
33 and 34 to protect the surfaces 33 and 34 from abrasive action
by the crushed materials 35.
The rim 16 of the frame assembly 12 constitutes a structurally
reinforced seat 16 for the bowl assembly 14. The bowl assembly may
be held centered in place against the seat 16 by an arrangement
which permits the bowl assembly to temporarily raise itself from
the seat 16 in yielding to excessive crushing forces. A yieldable
hold-down of the bowl assembly 14 is particularly needed when non-crushable
materials such as tramp iron passes through the crusher 10. A relief
may be provided in any of a number of known ways, including hydraulic
relief provisions. A yieldable arrangement may either lift the bowl
assembly 14 as in the present example, or a hydraulic relief may
cause the crusher head to deviate from a normal, circularly gyrating
crushing path around the bowl assembly 14. FIG. shows a known spring
relief arrangement 36. The arrangement 36 includes a plurality of
compression springs 37. The springs 37 are seated on respective
guide bolts 38 and are retained under a predetermined compressive
force by tension washers 39 secured to lower ends of the guide bolts
38 by lock nuts 41. The guide bolts 38 and respective compression
springs 37 of the arrangement 36 generally would be spaced evenly
about the outer shell 25.
The stationary bowl assembly 14 includes a cylindrical crusher
bowl 45. A bowl liner 46 is of concave shape and is attached to
an inner, concave support surface 47 of the crusher bowl 45. A feed
hopper 48 is shown as being mounted over a central feed port 50
through the bowl 45 and bowl liner 46. The feed hopper 48 may be
part of the bowl assembly 14 or may be separate from the crusher
10. The feed hopper 48 is generally desirable as a liner to protect
bowl 45 from abrasive contact with materials being fed through the
feed port 50 into the crusher 10.
A bowl flange 52 peripherally supports the crusher bowl 45 with
respect to the frame assembly 12. The bowl flange 52 also centers
the bowl assembly 14 on the central axis 30 with respect to the
crusher 10. Outer screw threads 53 on the crusher bowl 45 engage
inner screw threads 54 on the bowl flange 52. By rotating the crusher
bowl 45 with respect to the bowl flange 52 the crusher bowl 45
may be raised or lowered with respect to the crusher frame assembly
12. The vertical adjustment of the crusher bowl 45 establishes a
gap setting between the crusher bowl 45 and the crusher head assembly
18. An initial setting of the crusher bowl 45 with respect to the
crusher head assembly 18 may be changed to adjust for wear or to
change a critical close side setting (CSS) as a result of a change
in the length of the crusher stroke. It is understood that the rotational
height adjustment of the crusher bowl 45 is but one known way to
effect adjustments for wear. Other known crusher arrangements have
effected such adjustments by maintaining the crusher bowl vertically
stationary and by adjusting the head assembly toward or away from
the crusher bowl. Such latter adjustment is conveniently done by
hydraulic piston arrangements, particularly since the crusher head
assembly 18 would typically be accessible only from beneath any
such crusher. Rotating the crusher bowl 45 with respect to the bowl
flange 52 is found to be advantageous in that the operation is readily
performed because of ready access to the outside of the crusher
10.
Removal of the bowl liner 46 may be effected either by removing
the crusher bowl assembly in its entirety or by rotating the crusher
bowl 45 upward and lifting it from its bowl flange 52. The bowl
liner 46 becomes detached from the crusher bowl 45 by loosening
locknuts 56 and releasing typical liner clamp hooks 57 which engage
clamping ears 58 of the bowl liner 46.
The crusher head assembly 18 is a spherical pivot bearing type
head assembly. A crusher head 60 is supported for gyratory motion
along a spherically shaped bearing surface 61 of a crusher head
base 62 nested within a complementarily concave spherical socket
or seat 63. The crusher head 60 is of a frusto-conical configuration,
simply referred to, though, as being of conical configuration. An
outer conical wear liner or wear mantle 64 is fastened to a conical
mantle support frame 66. The support frame 66 may be a unitary support
member or may be comprised of separate structural elements including
the crusher head base 62 an intermediate spacer disk 68 and a
cap base 69 for example. The crusher head assembly also comprises
a guide shaft 70 as part of the crusher head 60. The guide shaft
70 extends downward from the crusher head base 62 giving the crusher
head 60 a resemblance of a mushroom. The crusher head 60 depicted
in FIG. may be assembled by first inserting the guide shaft 70 through
a central, counterbored aperture 71 in the crusher head base 62
and bolting a flange 72 at an upper end 73 of the guide shaft 70
to the base 62. The spacer disk 68 with the pre-attached cap base
69 may then be bolted centrally to an upper mounting surface 75
of the crusher head base 62. The outer conical wear mantle 64 would
thereafter be placed over the mantle support frame 66. The wear
mantle or liner 64 may include such ledges or mounting ears or hooks
as may be deemed necessary to retain the particular shape and size
of the mantle or liner 64 on the mantle support frame 66. Various
provisions capable of securing the wear mantle 64 to the support
frame 66 are known, including the use of clamping ears and corresponding
clamping hooks, such as the ears and hooks 58 and 57 on the bowl
liner 46. The wear mantle 64 is shown attached to the mantle support
frame 66 by a clamping plate 78 driven downward by a clamping bolt
79 to urge the mantle 64 onto the frame 66. A cover plate 80 may
be applied to protect the bolt 79 from impact forces of material
falling onto the crusher head assembly 18.
The spherical seat 63 supports the crusher head 60 generally along
the central axis 30 yet provides for spherical sliding movement
of the base 62 along the curvature of the spherical bearing surface
61. Any such sliding movement of the crusher head 60 from a vertical
results in an angular displacement or tilting of the crusher head
60 with respect to the central crusher axis 30. The amount of tilt
of the crusher head 60 is measurable as angular deviation between
the central crusher axis 30 and an axis 82 through the center of
the crusher head 60. The radius of curvature of the spherical bearing
surface 61 determines a position of an "apex" 83 at which
the axes 30 and 82 intersect when the crusher head is tilted while
remaining in full contact with the spherical seat 63. The position
of the apex 83 remains fixed during gyratory motion of the crusher
head 60. Gyratory motion of the crusher head 60 is a rotational
displacement of a tilted orientation of the crusher head 60 about
the central axis 30.
The spherical seat 63 is mounted to, or supported by, the head
support frame 27. An interposed tubular spacer element 84 may be
welded or otherwise fastened to an inner wall of the head support
frame 27. The seat 63 is assembled to the spacer element 84 in a
manner which supports the seat 63 centrally with respect to the
axis 30 and which establishes crushing force transmitting contact
from the crusher head 60 through the seat 63 and the spacer 84 to
the head support frame 27. The seat 63 has a opening 85 which is
also centered on the axis 30. The guide shaft 70 extends downward
through the opening 85 into a cylindrical chamber 86. The cylindrical
chamber 86 is bounded by an annular wall of a support cylinder 87
which may be a lower integral extension of the seat 63 or the cylinder
87 may be separate from, and function as an annular support for,
the seat 63. The chamber 86 is also centered on the axis 30. The
central opening or aperture 85 and the cylindrical chamber 86 are
of a sufficiently large diameter to permit free angular displacement
of the guide shaft 70 consistent with a maximum contemplated angular
excursion of the guide shaft 70 during gyratory crushing action
of the crusher head 60.
A radially disposed drive shaft 91 of the crusher drive assembly
20 is journalled in bearings 92 and 93. The drive shaft 91 is disposed
within a tubular housing 94 which protects the shaft and bearings
from contact by crushed materials, dust or the like. A pinion 95
at an inner end of the drive shaft 91 engages a horizontally disposed
annular drive gear 96 which revolves about the central crusher axis
30. The drive gear 96 has internal splines 97 which slidably engage
complementary splines 98 of an eccentric drive piston 99. The eccentric
drive piston 99 is rotatably supported within the support cylinder
87.
In one currently contemplated embodiment the eccentric drive piston
99 may be comprised of an upper eccentric socket portion 100 and
a lower sleeve portion 101. The eccentric socket portion 100 may
be an assembled structure including a base 102 and a cap 103. In
a preferred structure, the base 102 and the cap 103 both include
machined semi-spherical cavities 104 and 105 respectively. The
cavities 104 and 105 complement each other to form a spherical socket
or eccentric bearing cavity 106 which retains a spherical bearing
107. The eccentric bearing cavity 106 is disposed at a predetermined
distance of eccentricity from the center of the drive piston 99.
The drive piston is centered on the central axis 30 such that the
distance by which the eccentric bearing cavity 106 is offset from
the center of the drive piston determines the amount of eccentricity
of the bearing 107 with respect to the central axis 30. The bearing
107 has a bore 108 which extends on a diametrical axis through the
bearing 107 and receives, and provides support for, the guide shaft
70. The guide shaft 70 extends through the bearing 107 through
the eccentric socket portion 100 and toward the lower sleeve portion
101 of the eccentric drive piston 99. The drive piston 99 with the
eccentric socket portion 100 and the spherical bearing 107 revolve
as an assembly about the vertical crusher axis 30 to generate and
control the gyration or gyratory movement of the crusher head 60.
The bearing 107 retains the guide shaft 70 in its bore 108 to support
it for relative rotation with respect to the drive piston 99. Though
the combination of the drive piston 99 and the eccentric socket
portion 100 results in a predetermined, fixed eccentricity of the
socket portion 100 with respect to the vertical axis 30 it would
also be possible to have the socket portion 100 disposed at an adjustably
variable distance with respect to axis 30. For example, a double
eccentric may be used to provide for such a variable eccentric displacement
of the center of the bearing 107. The eccentric displacement of
the socket portion 100 and of the bearing 107 tilts the guide shaft
70 and the crusher head 60 with respect to the vertical axis 30.
Rotation of the drive piston 99 generates the desired gyration of
the crusher head 60.
Gyration of the crusher head 60 generates relative motion of various
intensity between several mutually adjacent ones of the described
surfaces. Major surfaces which movably support the crushing head,
for example the spherical bearing 61 and its corresponding seat
63 or those contributing to the generation of the gyratory motion,
the guide shaft 70 and the bearing 107 and other load supporting
surfaces with relative movement to adjacent surfaces are those surfaces
which may desirably be lubricated by oil or equivalent lubricants
pumped through typical feed pipes to the respective surfaces. Various
acceptable ways of advantageously supplying lubricants or load carrying
oils to the respective surfaces may be chosen. It is also known
to protect working surfaces with seals, retaining lubricants and
preventing abrasive material, such as dust, from getting between
relatively movable adjacent surfaces. Strips of sealing material
may be recessed in grooves peripherally disposed about major load
bearing, movable surfaces. Particular detailed implementation of
oil seals and of lubricating oil supply systems are contemplated
to follow typical, known applications.
As an alternative to supporting loads with oil layers between load
bearing surfaces, roller bearings may be employed in certain applications.
The use of roller type bearings does not, however, eliminate the
need for providing lubrication to the bearings. Also, the need to
protect roller or ball bearings from dust, may cause a need for
effective dust seals to take on particular significance. Various
options may be chosen in providing effective lubrication to the
components which exhibit relative motion an have a load supporting
function.
The splines 97 of the drive gear 96 engage the corresponding splines
98 of the eccentric drive piston 99 to transmit a positive, rotational
drive force from the drive gear 96 to the drive piston 99. The drive
piston 99 rotates within the support cylinder 87 in response to
a power input via the drive shaft 91 and the pinion 95. Additionally,
the eccentric drive piston 99 is mounted for sliding movement within
the support cylinder 87 coaxially with the central crusher axis
30 hence, for vertical movement within the crusher 10. The splines
97 and 98 remain in driving contact over a full range of vertical
movement of the drive piston 99 within the support cylinder 87.
It may be realized from the above that other positive drive arrangements
may be used to impart rotary motion to the drive piston 99 and support
the vertical sliding motion. However, splines are a well known device
for combining axial sliding movement of shafts with rotary power
transmission.
A positioning link 110 is shown attached through a thrust bearing
111 to a lowermost end of the drive piston 99. The thrust bearing
permits the link 110 itself to remain stationary while the drive
piston 99 is rotatably driven by the gear 96. The link 110 may be
coupled directly to any vertical positioning mechanism as indicated
by a double-headed arrow 112. For example, one embodiment of a positioning
mechanism may be a hydraulic mechanism or arrangement 112. A hydraulic
cylinder 113 (a portion of which is shown) may be coupled to and
interact with the link 110 and vertically adjust the position of
the link 110 to position, in turn, the drive piston 99 with respect
to the crusher head assembly 18. An alternative embodiment of the
positioning mechanism 112 may be a mechanical elevating linkage
112 as schematically shown in FIGS. 2 and 3.
The Crusher Operation
The eccentricity of the guide shaft 70 is determined by an offset
"E" of the socket 106 away from the central axis 30 of
the crusher 10. When rotational power is applied, as indicated by
arrow 115 driving the drive shaft 91 and the drive gear 96 the
drive piston 99 rotates within the support cylinder 87. The eccentric
offset of the spherical bearing 107 from the central axis 30 drives
the guide shaft 70 to move in a circular path about the central
axis 30. Though it is possible to rotate the spherical bearing 107
within the drive piston 99 it is preferred to have relative rotation
between the guide shaft 70 and the spherical bearing in driving
the guide shaft 70 in this manner. The spherical bearing 107 however,
pivots in a plane defined by the central vertical crusher axis and
the axis 82 which defines the angle of deviation of the crusher
head 60 with respect to the vertical axis 30. A vertical repositioning
of the eccentric drive piston 99 with respect to the crusher frame
assembly 12 changes the angle of deviation of the guide shaft 70.
The eccentric bearing tilts accordingly to provide full counter
support for developed crushing forces as the guide shaft 70 is driven
through its gyratory movement by the eccentric drive piston 99.
As the drive shaft gyrates about the apex 83 the entire crusher
head 60 gyrates about the apex 83 as the center of the bearing 107
describes the offset, circular path about the central axis 30. With
an established distance to the apex 83 and any set height of the
eccentric drive piston 99 the eccentricity "E" of the
center of the spherical bearing 107 with respect to the central
axis 30 maintains a constant angle of deviation of the crusher head
60 with respect to the central axis 30 of the crusher 10. The angle
of deviation by the crusher head 60 from the vertical defines the
stroke length of the crusher head 60. Total angular displacement
of the guide shaft 70 at the center of the bearing 107 over a single
revolution of the drive piston 99 amounts to twice the angle whose
tangent is defined by the ratio of the eccentricity "E"
divided by the distance from the center of the socket 106 to the
apex 83. All other elements of the crusher head 60 undergo the same
total angular displacement as that of the guide shaft 70.
The stroke of the crusher head 60 is measured as the difference
between the high point of gyration of the mantle 64 toward the bowl
liner 46 its closed side setting (CSS) indicated at 117 and the
maximum gap across the same section. Of course while any one peripheral
position is at the CSS 117 diametrically opposite from the minimum
crusher gap setting 117 a crusher gap 118 is at its maximum or
at an open position.
The gyratory crusher 10 is distinct with respect to other gyratory
crushers by the vertical adjustment capability of the eccentric
drive piston, the socket 106 and the corresponding spherical bearing
107. FIG. 1 shows the bearing support cavity or socket 106 to be
at a high end of its vertical adjustment range. A vertical downward
adjustment of the drive piston 99 and its eccentric socket portion
100 does not affect the vertical position of the crusher head 60
Instead, a downward adjustment of the drive piston 99 lengthens
the distance between the apex 83 and a portion of the guide shaft
70 through which the eccentric socket portion 100 controls the deviation
of the guide shaft 70 with respect to the central axis 30. The downward
adjustment of the eccentric socket portion 100 decreases the stroke
defining angle of deviation of the crusher head axis 82 from the
central axis 30. As a result the stroke of the crusher head 60 is
shortened as the drive piston is moved downward with respect to
a prior upper position. Conversely, when the drive piston 99 is
in a comparatively low position, the link 110 may raise the drive
piston 99 within the support cylinder 87 to lengthen the stroke
of the crusher head 60. It is to be noted that an axial adjustment
of the drive piston 99 with respect to the apex 83 results in an
angular change of the support bearing 107 within the socket 106
about an axis of rotation which is orthogonal to the crusher head
axis 82 centrally through the guide shaft 70. A function of the
support bearing 107 is to permit relative rotation between the drive
piston 99 and the guide shaft 70 while distributing lateral crushing
loads at the interface between the guide shaft 70 and the drive
piston 99. What is more significant, however, is that lateral crushing
forces exerted by the guide shaft 70 against the support bearing
107 continue to be uniformly distributed through the support bearing
107 with respect to the drive piston 99 even though the angular
relationship of the drive piston 99 and the guideshaft 70 may change
as a result of adjustment of the stroke. The spherical external
shape of the support bearing 107 provides for substantially uniform
force distribution over the range of relative movement among the
drive piston 99 the spherical support bearing 107 and the guide
shaft 70.
It will be understood by those skilled in the art that a lengthening
or shortening of the crusher stroke as provided for may also require
an adjustment of the closed side setting 117 to prevent an overload
on the crusher 10. A closed side setting adjustment is readily accomplished
by rotating the crusher bowl 45 with respect to the bowl flange
52 to raise or lower the crusher bowl 45 with respect to the crusher
head 60. The same adjustment is routinely performed on other known
crushers to compensate for wear on the bowl liner 46 and the mantle
64. A longer stroke has been found to increase the production capacity
of the crusher 10. Such increase in stroke length may optimize the
crushing operation of the crusher 10 when the materials to be comminuted
are easy to crush when compared to other crushable materials. Hence,
the stroke adjustment allows the crushing operation to be optimized
with respect to the characteristics of currently available materials.
The increased production capacity or material flow through may require
a gap increase at the closed side setting to accommodate increased
material flow. Also, a nominal increase in the crusher speed or
an increase in the available power to drive the crusher 10 may be
desired. A shortening of the stroke length may conversely become
necessary to again optimize the operation with respect to comminution
of a harder material as compared to a previously available material.
A contemplated embodiment may, for example have a deviation range
of the guide shaft 70 between 2 and 2.6 degrees. The crusher stroke
may accordingly vary between 1.6 and 2.3 inches. Of course, these
stroke adjustment ranges are given as an example only, and are not
to be considered limiting to the scope of the invention. Another
crusher 10 in accordance with the invention may provide a stroke
adjustment with a range of between 2 and 3 inches, for example.
FIGS. 2 and 3 are partial schematic representations of the crusher
10 showing, respectively, one of two different adjustment settings
of the drive piston 99 within the support cylinder 87 to further
illustrate the described stroke adjustment provisions. In FIG. 2
the spherical bearing 107 is disposed at an uppermost end of the
guide shaft 70 as it extends from the crusher head base 62. The
positioning mechanism 112 supports the eccentric drive piston 99
in a correspondingly uppermost position to render the crusher head
axis 82 at a maximum deviation with respect to the central crusher
axis 30. At this setting the bowl liner 46 is adjusted vertically
for a minimum gap setting at the closed side setting 117 with respect
to the wear mantle 64.
In FIG. 3 the positioning mechanism 112 has positioned the drive
piston 99 at substantially a lowermost position with respect to
the crusher frame assembly 12. The seat 63 still positions the crusher
head 60 at the same height with respect to crusher frame assembly
12. The apex 83 at which the centerline or axis 82 of the crusher
head intersects the central axis 30 of the crusher remains stationary
with respect to the crusher frame 12. However, the deviation of
the axis 82 from the axis 30 decreased, hence the angle of gyration
of the crusher head 60 about the central axis 30 is less. As a result
of the downward adjustment of the drive piston 99 the stroke of
the crusher head has become less. Concurrently with the decrease
of the angular deviation of the crusher head 60 with respect to
the central crusher axis 30 the closed side setting and the maximum
open setting between the wear mantle 64 and the bowl liner 46 have
changed. The closed side setting at 117 in FIG. 3 has increased
with respect to the closed side setting shown at 117 in FIG. 2
showing, of course, the bowl liner 46 in the original position as
also depicted in FIG. 2. Conversely, the maximum gap setting at
118 diametrically across the closed side setting 117 has decreased.
The stroke length of gyratory movement of the crusher head 60 has
consequently been decreased by a distance which is the sum of the
increase of the closed side setting 117 and the decrease of the
maximum gap setting 118 in FIG. 3 over the corresponding settings
shown in FIG. 2.
If an increase in the stroke length of the crusher head 60 is desired,
it may be prudent to first adjust the closed side setting 117 to
increase the gap between the bowl liner 46 and the crusher head
mantle 64 prior to moving the drive piston 99 upward within the
support cylinder 87. After adjusting the angle of deviation of the
crusher head 60 from the central axis 30 a fine tuning of the closed
side setting adjustment may be necessary.
Various changes and modifications of the described apparatus are
possible without departing from the spirit and scope of the invention.
It is to be realized that other gyratory crushers adjust the closed
side setting, such as at 117 by vertically moving the respective
crusher heads instead of adjusting the bowl liner 46 as described
with respect to FIG. 1. It is possible to use the present invention
with either type of gyratory crusher. Also, various types of crusher
heads, such as short heads and long heads are used for different
types of crushing requirements. The invention is applicable to gyratory
crushers with either short or long crusher heads. It is furthermore
possible to apply the invention advantageously to different types
of gyratory crushers, though a different crusher head gyration mechanism
may necessitate some changes in the arrangement of the described
elements for adjusting the crusher stroke length. The advantage
of varying the stroke length applies generally to gyratory crushers
regardless of the mechanism by which the gyratory motion of the
crusher head is produced. The particular structure of a gyratory
crusher 10 and stroke control arrangement may use a cylindrical
coupling member in lieu of a spherical bearing to seat the guide
shaft 70 for rotation within the drive piston 99. The described
structure is therefore set forth as an example of a currently preferred
apparatus embodying the features of the present invention and not
as a limitation to its scope. |