Abstrict A gyratory crusher of the type including a frame with a bowl mounted
on the frame and a head cooperable with the bowl in crushing operations.
The head is rotatably mounted on an eccentric which is driven through
suitable gearing. The head is positively rotated by a drive means
either independent of or integral with the drive for the eccentric.
The bowl is free to rotate about the frame. The rotary motion imparted
to the head serves to induce centrifugal force to the particles
of material within the crushing chamber. This centrifugal force,
when combined with the gravitational force acting on the particles
of material, results in the material moving through the crushing
chamber in a trajectory which follows the configuration of the crushing
chamber.
Claims I claim:
1. A method of crushing material comprising the steps of providing
a crusher including a bowl rotatable about its own axis and a head
cooperating with said bowl to define a crushing chamber therebetween
having an inlet and an outlet; providing the crushing chamber with
a curved shape that is flatter at its outlet than at its inlet;
inducing a gyratory motion in the head to cause the head to move
alternately toward and away from the bowl to impart a crushing force
to material in the crushing chamber; positively and independently
rotating the head at a speed to impart centrifigal force to particles
of material in the crushing chamber which centrifugal force combines
with gravitational force acting on particles of material in the
crushing chamber to move material through the crushing chamber on
a curved trajectory; controlling the speed at which the head is
rotated to control the amount of centrifugal force applied to particles
of material in the crushing chamber whereby when the speed of rotation
is increased the centrifugal force increases and the trajectory
of material moving through the crushing chamber becomes flatter;
and coordinating the speed of rotation of the head with the shape
of the crushing chamber so that the trajectory of material moving
through the crushing chamber substantially conforms with the shape
of the crushing chamber.
2. A rock crusher comprising:
a frame;
a bowl rotatably mounted on said frame and free to rotate about
its own axis;
a head cooperable with said bowl to define a crushing chamber therebetween;
an eccentric rotatably mounted on said frame and operatively connected
to said head;
first means for rotating said eccentric for causing said head to
gyrate relative to said bowl including a ring gear secured to said
eccentric and a drive shaft operatively connected to said ring gear;
second means for positively rotating said head relative to said
eccentric for imparting a centrifugal force to particles of material
in the crushing chamber which centrifugal force when combined wih
gravitational force acting on the particles of material move the
particles of material through the crushing chamber on a trajectory;
said second means including a planetary gear means mounted on said
ring gear, a sun gear operatively connected to a second drive shaft
and said panetary gear means, and a head gear operatively connected
to said head and to said planetary gear means and head gear whereby
said head is positively rotated by said second drive shaft, sun
gear, planetary gear means;
said crushing chamber having an inlet and an outlet and having
a configuration that is flatter at its outlet than at its inlet
and substantially conforms in shape to the trajectory of particles
of material moving through the crushing chamber.
3. A rock crusher comprising:
a frame;
a bowl rotatably mounted on said frame;
a head cooperable with said bowl to define a crushing chamber therebetween
having an inlet and an outlet and a configuration which is flatter
at its outlet than at its outlet than at its inlet;
an eccentric rotatably mounted on said frame and operatively connected
to said head;
first means for rotating said eccentric for causing said head to
gyrate relative to said bowl to exert a crushing force on material
within the crushing chamber including a ring gear secured to said
eccentric and a drive shaft operatively connected to said ring gear;
and
second means for postively rotating said head relative to said
eccentric for imparting a centrifugal force to particles of material
in the crushing chamber which centrifugal force when combined with
gravitational force acting on the particles of material move particles
of material through the crushing chamber on a trajectory; ;
said second means including a planetary gear means, a frame gear
mounted on said frame, a head gear mounted on said head and said
planetary gear means is adapted to revolve around said frame gear
to thereby rotate said head gear and said head;
said crushing chamber having a shape that substantially conforms
to the trajectory of particles of material moving through the crushing
chamber.
Description BACKGROUND OF THE INVENTION
The present invention relates to gyratory crushers in general and,
more particularly, to a gyratory crusher of the type which is designed
to be a secondary or tertiary crusher in the size reduction of material
being removed from a quarry or mine.
Gyrator crushers typically include a rotary means or eccentric
mounted by means of bearings on the frame and in some cases, on
a main shaft of the frame. A crushing head is mounted by means of
bearings on the eccentric at an angle to the frame. The eccentric
is rotated through a drive shaft and gearing and as it rotates relative
to the frame, the head of the crusher moves alternately toward and
away from the bowl of the crusher in a gyratory manner. As material
to be crushed moves through the crushing chamber, it is repeatedly
subjected to compressive forces and reduced in particle size. Typically,
there is a certain amount of drag in the bearings between the eccentric
and the crushing head so that the crushing head not only gyrates
but also rotates uninhibited about its own axis at less than 15%
of the number of gyrations per minute during the crushing operation.
Many crushers prior to the present invention provided some means
for preventing rotation of the head or at least reducing the speed
or rotation of the head during crushing operations; See U.S. Pat.
No. 3908912 and the anti-spin mechanism in various other patents.
It is the general object of a rock crusher to reduce the size of
the material being supplied to the crushing chamber at as rapid
a rate as is practical with the smallest machine practical. Conventionally,
material moves through the crushing chamber by the force of gravity
and a small amount of movement added to the material by the oscillations
of the crushing head. As a result, the material movement through
the crusher is generally slow and the material is often subjected
to a greater number of compressions than is actually necessary to
reduce the size of the material to the desired fineness. As a result,
in many instances, more "fines" are produced than is desired.
These fines must be screened off in order to achieve the desired
product size range. In order to move sufficient material through
the crusher to achieve the desired capacity, it has heretofore been
necessary to have a large machine.
In order to increase crusher capacity, it would be desirable to
arrive at a means and method for moving a greater volume of material
through the crusher while still being able to subject this material
to sufficient number of impacts or compressions to achieve the desired
size reduction. Conventionally, this is done by providing a larger
machine or operating a machine at a faster speed.
In an effort to increase the amount of material which can be passed
through a gyratory crusher and still achieve the desired size reduction,
it has been proposed to rotate the bowl of the crusher relative
to the crushing head as shown in U.S.S.R. Author's Certificate No.
579011 published Nov. 5 1977. According to this publication, centrifugal
forces contribute to push material towards the discharge opening
of the crusher.
By imparting a centrifugal force to the material being crushed,
a generally horizontal force is imparted to the particles of material.
Gravitational force imparts a vertical force to the material being
crushed. If the centrifugal force imparted to the material can be
controlled, then the vector sum of the combined gravitational and
centrifugal forces acting on a particle of material within the crushing
chamber at any given point can be controlled. The vector sum is
such that the material is moved through the crushing chamber at
a greater speed. The crushing chamber can then be designed so it
generally conforms with the trajectory of material moving through
chamber. This means that the crushing chamber can be designed so
that the material moves through the crushing chamber at a speed
which, when coordinated with movement of the crushing head permits
a greater volume of material to be passed through the crusher while
achieving the desired size reduction but without compressing the
material so many times that additional fines are produced. By being
able to move material through the crushing chamber at a faster rate,
a given size machine can produce a greater volume of product. In
addition, a trajectory path formed by the compression members (head
and bowl) which is closely related to the vector sum of the gravitational
and centrifugal forces reduces the per ton wear rate of the crushing
members.
In order to achieve this desired combination of circumstances,
it has been found by the present invention that the means for producing
an oscillating motion in the crushing head to thereby subject the
material to compressive crushing forces should be capable of being
independent of the means for imparting centrifugal force to the
material being crushed. This allows a control over each of the functions.
The centrifugal force imparted to the material within the crushing
chamber can be carried out by positively rotating either the crushing
head independently of the gyratory motion induced in the crushing
head or by independently rotating the bowl of the crusher, or by
rotating both. It has also been found by the present invention that
it is only necessary to rotate one of the crushing members, i.e.,
either the crushing head or the bowl of the cruhser and allow the
other curshing member to freely rotate. The material within the
crushing chamber thereby acts as a clutch between the two crushing
members so that both are positively rotated. It should be noted
that both crushing members could be rotated and still be within
the concepts of the present invention.
SUMMARY
It is the principle object of this invention to provide a crushing
apparatus which is capable of processing a greater volume of material
than prior apparatus while still achieving the desired size reduction
of the material.
It is a further object of the present invention to provide a crushing
apparatus which is capable of processing a large volume of material
but reduces the production of undesired oversized and undersized
product which requires additional screening capability or generation
of waste product.
In general, these and other objects will be carried out by providing
apparatus for crushing material comprising first and second crushing
members defining a crushing chamber therebetween; first means for
producing a gyratory motion in one of said crushing members whereby
said one of the crushing members moves alternately toward and away
from the other crushing member to thereby impart crushing forces
to material within the crushing chamber; and second means for producing
a rotary motion in one of said crushing members for imparting centrifugal
force to the material within the crushing chamber; said second means
being variable from and operating at a speed different from said
first means.
The foregoing and other objects of the invention will also be carried
out by providing a method of crushing material comprising the steps
of providing first and second crushing members which define a crushing
chamber; causing at least one of the crushing members to move alternately
toward and away from the other crushing member to thereby impart
a crushing force to material within the crushing chamber; and independently
inducing a motion to the material being crushed which motion has
a primary component in a direction to advance material through the
crushing chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in connection with the annexed
drawing wherein:
FIG. 1 is a diagrammatic view partially in section of a crusher
of the prior art;
FIG. 2 is a sectional view of a crusher according to the present
invention; and
FIG. 3 is a diagram of the trajectory of a particle of material
moving through the crushing chamber of the present invention; and
FIG. 4 is a view similar to FIG. 4 showing a modification of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 a typical prior art crusher includes a frame
1 having a main shaft 2 and an eccentric or rotary means 3 rotatably
mounted on the shaft 2 and frame 1 by means of bearings 4. A crushing
head 5 is rotatably mounted by means of bearings 6 and 7 on the
eccentric 3. A suitable drive mechanism formed by a drive shaft
8 and gearing 9 and 10 serves to rotate the eccentric 3 to impart
an oscillating or gyratory motion to the crushing head 5. The crusher
also includes a bowl 11 which with the head 5 defines a crushing
chamber 12. As eccentric 3 is rotated around the main shaft 2 the
head 5 moves alternately toward and away from the bowl 11 in a gyratory
manner to thereby impart compressive forces to material within the
crushing chamber 12 and crush the material.
In most compression crushers available in the marketplace today,
gravitational force is the primary motive force which advances material
through the crushing chamber 12. The oscillations of the head 5
serve to induce some movement of the material through the crusher,
but this is limited due to the desire to keep the magnitude of the
oscillating movement of the head within reasonable limits.
In many crushers, it is not unusual to include a means 14 for preventing
the head 5 from rotating with the eccentric 3.
It has been found by the present invention that it is desirable
to induce a centrifugal force in the particles being crushed so
that a generally horizontal component of force is imparted to the
material being crushed to thereby permit a faster movement of material
through the crushing chamber. One means for carrying out this concept
is illustrated in FIG. 2.
In FIGS. 2 and 4 the crusher includes a frame 20 which may be
similar to the frame of a crusher of the prior art. A rotary means
on eccentric 21 is rotatably mounted in the frame 20 by means of
bearings 22 and 23 through an adjusting mechanism generally indicated
at 24.
The adjusting mechanism 24 includes an annular support member 25
which is keyed at 26 to the frame 20 to permit the member 25 to
move vertically relative to the frame. The support 25 is provided
with internal screw threads 25a. An annular adjusting member 27
is rotatably mounted on frame 20 by means of bearing 28. Annular
support member 25 is connected to member 27 through threads 25a
and 27a. A worm gear 29 engages teeth 30 on the outer periphery
of annular member 27. When the worm 29 is rotated, member 27 is
rotated causing the vertically movable, rotatably fixed annular
member 25 to move in a vertical direction by means of the threaded
connection 25a-27a to thereby provide a means for adjusting the
vertical position of the eccentric 21.
A ring gear 33 is keyed at 34 to the eccentric 21. Bearings 35
are used between the ring gear 33 and annular adjusting member 27.
A bevel gear 36 mounted on a shaft 37 engages gear 33. Shaft 37
is mounted in bearings 38 and 39 in the frame 20 in a well-known
manner and adapted to be connected to a motor (not shown). Thus,
the motor, the shaft 37 and gears 36 and 33 and key 34 define a
means for rotating the eccentric 21.
A crusher head 42 is rotatably mounted on the eccentric 21 by means
of bearings 43 and 44. As is typical in a crusher of this type,
the head 42 is mounted so that its axis 45 is at an angle to the
centerline or axis 40 of the crusher and the centerline of the eccentric.
The centerline of this eccentric may, if desired, be parallel to
but offset from the centerline of the crusher. Due to the angled
crushing head, as the eccentric 21 is rotated, the head 42 gyrates
or oscillates relative to the crusher frame 20.
A seal 46 may be provided around the periphery of the head 42 to
prevent crushed rock from entering the various bearings.
The crusher frame includes an upper shell 48 having a bowl or concave
49 rotatably mounted on the frame 20 by means of bearings 50 and
51. The bowl 49 is aligned with the axis 40 of the crusher.
Wearable material 54 is mounted by conventional means on the bowl
49. Wearable material 55 is also mounted on the head 42 and defines
therebetween a crushing chamber 56 having an inlet 57 and an outlet
58. The adjusting mechanism 24 serves to move the head 42 toward
or away from the bowl 49 to thereby vary the discharge size of the
crushing chamber 56. As is well known to those skilled in the art,
this adjustment permits changing the product size and permit adjustment
of the crusher to compensate for wear of the wearable material 54
and 55.
In general, crushing takes place by one of the crushing members
defined by the head 42 and wearable material 55 alternately moving
toward and away from the other crushing member defined by bowl 49
and wearably material 54 so that a crushing or compressive force
is imparted to material within the crushing chamber. Thus, the drive
shaft 37 gearing 36 and 33 and rotary means 21 define a means for
causing one of the crushing members to move alternately toward and
away from the other crushing member of a first means for producing
a gyratory motion in one of the crushing members whereby said one
of the crushing members moves alternately toward and away from the
other cruhsing member to impart crushing forces to material within
the crushing chamber 56. Large pieces of stone to be crushed are
supplied from the primary crusher of quarry to the inlet 57 of the
crushing chamber. The movement of the head toward the bowl imparts
crushing forces to the material to break it into smaller pieces.
When the head moves away from the bowl, these broken pieces fall
by means of gravity through the crushing chamber 56. This movement
is stopped when material is again pinched between the two crushing
members and the material is further broken. This action is repeated
until the material is discharged from the crushing chamber 56 through
outlet 58 and material is discharged from the crusher through outlet
60.
In a conventional crusher such as shown in FIG. 1 in order to
increase production, the crusher is operated at a higher speed with
consequent larger motions and thicker material streams. The result
is that the head 5 moves toward and away from the bowl 11 more times
so that the material is subjected to a greater number of impacts.
The result is a greater production of fine material which in many
instances must be screened off to produce the desired product. Another
manner of increasing production is to use a larger machine.
By the present invention, I have provided a means for increasing
the amount of material which can be put through the machine while
achieving the desired size reduction, but without producing excessive
fines or oversize product. This will reduce the amount of screening
required to obtain the desired finished product size. In general,
this is carried out by providing an independent means for producing
a rotary motion to one of the crushing members which rotary motion
imparts a centrifugal force to material within the crushing chamber.
The means for imparting centrifugal force includes a planetary
gearing means 64 mounted on the hub 63 of ring gear 33. The planetary
gearing means includes a shaft 65 rotatably mounted by means of
bearings 66 and 67 in an enlarged portion of hub 63. Gears 68 and
69 are mounted on shaft 65. In FIG. 2 an independent shaft 71 is
fixed to frame 20 and has mounted thereon a fixed gear 72 which
meshes with gear 68 of planetary means 64. A shaft 74 is keyed to
the head 42 and gear 75. The gear 75 is mounted on the eccentric
or rotary means 21 and is secured thereto by bearings allowing the
gear to rotate at a speed independent of the eccentric speed. The
shaft 74 and gear 75 are designed to extend into but rotate relative
to hub 63 and ring gear 33.
In operation of the crusher, the drive shaft 37 is driven by a
motor means to rotate gear 36 and ring gear 33 to cause head 42
to gyrate as described above. Rotation of ring gear 33 about its
own axis causes planetary gear means 64 to revolve about the axis
of the ring gear. Due to the gears 68 and 69 being mounted on the
shaft 65 when planetary means 64 revolves around fixed, frame gear
72 gear 68 shaft 66 and gear 69 are rotated. The rotation of gear
69 produces a rotary motion in meshing gear 75 to thereby rotate
head 42 relative to frame 20.
The planetary means 64 is mounted so that its axis 78 is at an
angle to both the axis of the eccentric 21 and the head 42.
By varying the relationship to each other of the reduction ratios
of the gears 68 72 69 and 75 the head 42 can be rotated at a
desired speed independent of the speed at which the head moves alternately
toward and away from the bowl or concave 49. While the drive means
64 72 74 and 75 receives its driving force from the same source
as the direct drive 37 36 33 for the eccentric 21 the gearing
used makes the rotational drive independent or variable from the
drive which produces the gyratory motion.
Rotation of the head 42 serves to impart a centrifugal force to
particles of material within the crushing chamber 56. This centrifugal
force acts horizontally on the material being crushed and when combined
with the gravitational forces acting on the material within the
crushing chamber serves to produce a resultant vector. In FIG. 3
the gravitational force at any given point within the crushing chamber
56 is indicated by the vector G and the centrifugal force at that
point is indicated by the vector C.
While the gravitational force is constant, the velocity of the
head 42 at the crushing chamber or surface of the wearing material
54 increases toward the bottom of the crushing chamber so that the
centrifugal force imparted to a particle of material in the crushing
chamber 56 will, in the configuration shown, also increase. As a
result, the trajectory of a particle of material may, at least to
a certain extent, be controlled. One such trajectory is shown in
FIG. 3 and designated at T. With the present invention, the crushing
chamber is designed so that it has a configuration which is generally
in accordance with the designed trajectory. This permits a crushing
chamber which allows the maximum amount of material to be moved
through the crusher by the combined gravitational/centrifugal forces
yet the material will be sujected to sufficient impacts to produce
the desired size reduction. In addition, because the crushing chamber
56 closely approximate the trajectory of material moving therethrough,
wear of the material 54 55 will be reduced.
Thus, a means has been defined for independently inducing a motion
to the material being crushed, which motion has a primary component
in a direction to advance material through the crushing chamber.
The trajectory T can have a steeper angle or more vertical than
illustrated in FIG. 3 by reducing the centrifugal force by reducing
head rotational speed. The crushing chamber can have a path so that
trajectory T is more horizontal by increasing the speed of rotation
of the head 42 so that a greater centrifugal force is imparted to
the material to be crushed. If the shape of the crushing chamber
is flattened, this greater centrifugal force can serve to increase
the speed at which the material moves through the crushing chamber.
While the centrifugal force serves to aid in the movement of material
thorugh the crusher, the conventional rotary means 21 and direct
drive means 37 36 and 33 serves to control the number of times
material is subjected to crushing forces during the movement through
the crushing chamber 56. The fact that the second drive means 64
72 74 and 75 for imparting a centrifugal force to the material
is independent of or variable from the means 37 36 and 33 for
imparting crushing forces to the material allows a machine to be
designed which permits maximum throughput for a desired size reduction.
The speed of the gyratory motion is coordinated with the speed of
the rotation motion so that material moves through the crushing
chamber at the desired rate while achieving the desired size reduction.
The actual speeds and their relationship to each other will depend
upon the capacity desired, the size reduction desired and the material
being crushed.
By the present invention, it is believed that in order to achieve
the desired centrifugal force on the material being crushed, it
is necessary to have the bowl freely rotatable. The material within
the crushing chamber acts as a clutch between the two crushing members.
If one of the crushing members were fixed and the other driven,
excessive forces would be placed on the machine.
From the foregoing, it can be seen that a novel method of crushing
material has been devices which includes causing a crushing member,
i.e., the head, to move alternately toward and away from the crushing
member, i.e., the bowl, to thereby impart crushing forces to material
within the crushing chamber. The method also includes independently
inducing a motion of the material being crushed which motion has
a primary component in a direction to advance material thorugh the
crushing chamber. This independent motion is accomplished by rotating
the head independently of the gyratory motion imparted to the head.
The rotary motion of the head imparts a centrifugal force to the
material within the crushing chamber and this centrifugal force
combined with the gravitational force acting on the particles of
material serves to advance material through the crushing chamber.
While in the embodiment shown in FIG. 2 the head is driven to provide
the means for imparting a centrifugal force to the material, in
other embodiments, it may be desirable to positively rotate the
bowl and have the head freely rotatable. It may also be desirable
to positively rotate both. Other arrangements may also be used for
the drive of the head; some of which may utilize an independent
motor for rotating the head, and employ suitable gearing to achieve
the desired independent control. One such configuration is shown
in FIG. 4.
Referring to the embodiment of FIG. 4 wherein like numerals reference
like parts, there is provided a separate drive means generally indicated
at 80 for producing rotary motion of the crushing member 42. In
this embodiment, the second drive means 80 includes a drive shaft
81 adapted to be connected to a motor (not shown) and a sun gear
82 which takes the place of the fixed gear 72 of the embodiment
of FIG. 3 and meshes with planetary gear 68 of means 64.
The positive rotation of gear 82 produces a positive rotation of
gear 68 and has gear 69 to rotate head gear 75 and thus crushing
member 42. The embodiment of FIG. 4 thus provides not only an independent
means for rotating head 42 and thus imparting centrifugal force
to particles within the crushing chamber, but also a means for positively
rotating head 42.
It should be pointed out that while the invention has been illustrated
in connection with a sleeve bearing type crusher, it is to be understood
that its principle can be applied to any gyratory crusher.
From the foregoing, it should be apparent that the invention has
been described as a preferred embodiment. It is intended, however,
that the invention be limited solely by that which is within the
scope of the appended claims.
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