Abstrict In a gyratory crusher the crusher head is mounted on a drive shaft
which is driven by an eccentric. The eccentric is continually rotated
to cause the head to gyrate for effecting the crushing of material.
an antispin arrangement is provided to prevent rotation of the crusher
head in the same direction as the eccentric under idling conditions
or no load conditions. The antispin device includes a pair of ratchets
one of which is coupled to the shaft and the other of which is formed
on the end face of a piston which is held in the counterbore of
the drive shaft by a spring. A rectangular torsion rod extends through
the center of the piston into a clearance hole bored in the crusher
head drive shaft. The top of the torsion rod is anchored in the
spider cap of the crusher.
Claims The embodiments of the invention in which an exclusive property
or privilege is claimed are defined as follows:
1. In a gyratory crusher having a frame including a spider, a crusher
head carried by a shaft which is supported by the frame for rotation
about its own axis and for gyratory movement about the axis of the
frame and a drive eccentric operable to effect the gyratory movement
of the shaft and crusher head:
an axial bore in the shaft, said axial bore having a counterbore;
a first ratchet plate having an axial opening the diameter of which
is substantially equal to the diameter of said bore in the shaft,
said first ratchet being disposed at the bottom of the counterbore
and secured therein to rotate with the shaft;
a second ratchet plate disposed in the counterbore in operating
engagement with said first ratchet plate;
means in said second ratchet plate defining a non-circular opening
therethrough;
a torsion rod of noncircular configuration of cross-section secured
to the spider and depending downwardly therefrom into said axial
bore formed in the shaft, said torsion rod extending through the
openings in said first and second ratchet plates, said opening in
said second ratchet plate being sized to give clearance to said
torsion rod in all vertical positions of the shaft but sufficiently
small enough wherein upon limited rotation of said second ratchet
plate the sides of the opening engage with said torsion rod to stop
further rotation of said second ratchet whereupon said first and
second ratchet plates in cooperation with said torsion rod operate
to prevent the further rotation of the shaft in the direction in
which the drive eccentric is rotating; and,
a spring confined within the counterbore and acting against said
second ratchet plate to bias said second ratchet plate into operating
engagement with said first ratchet plate, said spring yielding when
the crusher is under load to permit the shaft to rotate in a direction
opposite to the direction in which the drive eccentric is rotating.
2. A gyratory crusher according to claim 1 including a cup-shaped
piston disposed within the counterbore;
said second ratchet plate being formed on the bottom face of said
piston; and,
said spring is disposed in said cup-shaped piston and operates
to urge said piston downwardly to effect an operative engagement
of the ratchet formed on the bottom surface thereof with said first
plate.
3. In a gyratory crusher having a frame, a crusher head carried
by a shaft which is supported by the frame for rotation about its
own axis and for gyratory movement about the axis of the frame,
and a drive eccentric operable to effect the gyratory movement of
the shaft and crusher head;
a first ratchet member secure to the shaft;
a second ratchet member disposed in co-operating relationship with
said first ratchet member;
a bar having one end secured to the frame and having its opposite
end in position to be engageable with said second ratchet member
upon limited rotation of said second ratchet member with respect
to said first ratchet member in the direction in which the shaft
is rotating to stop the further rotation of said second ratchet
member and thereby prevent rotation of the shaft in the direction
in which the drive eccentric is rotating when the crusher is idling;
and,
a spring carried by the shaft and operable on said second ratchet
member to yieldably maintain said second ratchet member in engagement
with said first ratchet member;
whereby the shaft and thereby the crusher head are allowed to rotate
in a direction opposite to the direction that the drive eccentric
is rotating when the crusher is under load.
Description BACKGROUND OF THE INVENTION
The invention pertains to gyratory crushers for reducing material
to desired sizes. More particularly, the invention pertains to a
gyratory cone type crusher in which the crushing head is carried
on a shaft which is rotatably driven by an eccentric so that the
head is gyrated upon rotation of the eccentric. A problem which
is frequently encountered in gyratory crushers is the fact that
the cone crusher head in running idle or no load condition tends
to rotate with the eccentric. The cause of the spinning is the frictional
drag that occurs between the crusher head shaft and the eccentric
drive mechanism. If the spinning is excessive, it can damage the
contact oil seals and bearings. Also, when material is fed into
the crusher in which the crusher head is spinning, excessive wear
of the crushing surfaces can occur due to skidding between the surfaces
and the material. To prevent such crusher head spinning many approaches
have been taken with varying degrees of success.
Examples of crushers in which antispin devices are incorporated
are shown in U.S. Pat. Nos. 1960980; 3207449; 3473743; 3539119
and 3743193.
However, in a crusher where the crusher head shaft is adjustable,
the anchor point of the antispin device can be fixed to the stationary
frame. In this arrangement, provision must be made to allow the
antispin device to work for all possible crusher shaft positions.
When the crusher is idling the crusher head shaft tends to spin
in the same direction as the drive eccentric rotates. When the crusher
is working the crusher head shaft rotates slowly in the opposite
direction with respect to the direction in which the drive eccentric
is rotating. Thus, an antispin device must allow for this reverse
rotation.
SUMMARY OF THE INVENTION
The present invention includes among its objects the provision
of an improved means for an antispin device which is operable in
all possible crusher head shaft positions and allows for the reverse
rotation of the shaft under load.
In the present invention a piston is held in a counterbore of the
crusher head shaft by means of a spring and retaining plate. The
bottom face of the piston is one-half of a ratchet. The other half
of the ratchet is a plate which is fixed to the crusher head shaft.
A torsion rod which is rectangular in cross-section extends through
the center of the piston and extends beyond the plate into a clearance
hole bored into the crusher head shaft. The top of the torsion rod
is anchored to the stationary spider cap .
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view in vertical section through a gyratory crusher
in which the present invention is embodied;
FIG. 2 is an enlarged view in vertical section through the antispin
device of FIG. 1;
FIG. 3 is a view in horizontal section taken in a plane represented
by the line III--III in FIG. 2; and,
FIG. 4 is an enlarged developed view of the ratchet plates showing
tooth arrangements.
DESCRIPTION OF THE INVENTION
Referring to FIG. 1 of the drawing, there is shown a gyratory crusher
10 having a frame generally indicated at 11 and including a lower
frame section 12 and an upper frame section 14. The lower frame
section 12 includes a fixed vertical hub 16 having an upper portion
17 and a lower portion 18. The lower hub portion 18 is provided
with a closure plate 19 which forms sealed chamber 21. The closure
plate 19 also provides for a hydraulic fluid inlet 22 which communicates
with expansible chamber 21.
The upper frame section 14 opens upwardly and has secured therein
a concave ring 23 which is supported in coaxial relationship above
the hub 16. A generally conical crushing head 24 projects upwardly
within the concave ring 23 to define therebetween a crushing chamber
25. The crushing head 24 is supported and arranged with its central
axis inclined relative to and intersecting with the vertical axis
of the hub 16 and concave ring 23. The axes intersect at a point
X in a horizontal plane which passes through the middle of a bearing
26. The crushing head 24 has a central upwardly tapering bore 27
which is adapted to receive a tapered or frusto-conical portion
32 of a crusher shaft 33.
A nut 34 is threadedly engaged on the crusher shaft 33 at a position
adjacent the upper end of the crusher head 24 and serves to lock
the crusher head in operative position on the shaft 33. The upper
portion of the crusher shaft 33 is fitted with a bearing sleeve
36 and is received in the pivot bearing member 26. A spider 38 being
an integral part of the top of the frame 11 presents an axial hub
39 the axis of which coincides with the axis of the frame. The
hub 39 serves as a housing for the pivot bearing 26. A cap 41 having
an axially extending sleeve portion 42 is secured to the outer end
face of the hub 39 and locks the outer race of the pivot bearing
26 in the hub. A crusher head antispin device 45 is accommodated
in a suitable stepped bore 40 formed in the upper end of the crusher
head shaft 33.
The lower end of the crusher head shaft 33 is provided with a bearing
sleeve assembly 46 which is journalled in the inner race of a radial
bearing 47. A nut 48 threadedly engaged on the outer member of the
bearing assembly 46 is formed with an axially extending sleeve portion
which abuts the inner race of the radial bearing 47 to lock it in
position. The outer race of radial bearing 47 is supported in a
bore 51 of a drive eccentric 52. A bearing surface formed on the
exterior of the drive eccentric 52 receives the inner race 53 of
a radial bearing 55. The outer race 56 of the bearing 55 is disposed
in a circular seat 57 formed on the upper portion 17 of the vertical
hub 16. A nut 58 is threadedly engaged on a circular extension of
the drive eccentric 52 and is disposed to abut the inner race 53
of the bearing 55.
An axial thrust bearing 60 is disposed beneath the crusher head
shaft 33 between the lower axial end face thereof and a piston 61
within a cylinder 62 defined by the closure plate 19. Lubrication
of the thrust bearing 60 is accomplished through a communicating
oil passage 66 formed in the head of the piston 61. The passage
66 communicates with a vertical oil groove 67 in the exterior surface
of the piston. Lubricating oil from a source (not shown) is supplied
to the vertical groove 67 via a passage 68 that connects with the
vertical groove 67 via a port 69 drilled in the sleeve liner 71
of the cylinder 62.
To drive the crusher, a pinion gear drive shaft 76 is journalled
in bearings 77 and 78 carried by a bearing carrier 79 which is disposed
within a laterally extending hub 80 formed with the lower portion
18 of the frame section 16. The shaft 76 is driven by any suitable
source of power. At its inner end, drive shaft 76 carries a pinion
drive gear 81 that is in meshing engagement with a gear 82 connected
to the drive eccentric 52. Thus, shaft 33 is free to move axially
up and down within the bearing sleeve assembly 46 while still maintaining
its gyratory drive connection with the drive eccentric 52.
In the operation of the crusher 10 power is applied to drive the
pinion 81 and rotate the gear 82. This effects rotation of the drive
eccentric 52 which rotates in an orbit about the vertical axis of
the crusher. Thus, the axis of the crusher head shaft 33 is driven
in a gyratory motion and transcribes a cone about the central vertical
axis of the crusher. This motion provides the crushing action of
head 24 in the crushing chamber 25. As the crusher head shaft 33
is driven in its gyratory motion about the central vertical axis
of the crusher, crushing forces which are the result of stone being
broken between the head 24 and the concave 23 develop forces which
react on the head 24. These forces cause the head 24 and thereby
the shaft 33 to rotate slowly in the opposite direction to the eccentric
52 rotation about the axis of the crusher head shaft 33 while the
crusher head shaft is being bodily moved in a gyratory path of travel
about the central vertical axis of the crusher.
Vertical support and positioning of the crusher head 24 for adjusting
the opening of the crushing chamber 25 is accomplished by hydraulic
fluid under pressure. For this purpose, hydraulic fluid under pressure
is supplied to the expansible chamber 21 via the passage 22 in the
closure plate 19. The fluid under pressure in chamber 21 reacts
on the piston 61 elevating the shaft 33 and thereby the crusher
head 24 (or lowers the assembly) as desired.
As previously mentioned, the gyratory crusher 10 is provided with
an antispin device 45 to prevent undesirable spinning of the crusher
head 24. As shown in FIGS. 2 3 and 4 the crusher head shaft 33
is provided with an axially extending bore 91 having a counterbore
92. The counterbore 92 is, in turn, counterbored as at 93. A cup-shaped
piston 94 is slidably disposed within the counterbore portion 92
and held therein by operation of a spring 96. The spring 96 is retained
within the piston 94 by means of a retainer washer 97 that is disposed
at the bottom of the bore 93 adjacent the upper end of the counterbore
92. A snap ring 98 operates to lock the washer 97 in position.
The bottom or lower axial end face of the piston 94 is formed with
sloping surfaces 102 presenting vertical surfaces 103 and serves
as a ratchet 105. A plate 107 having an axial opening 108 is formed
with sloping surfaces 109 presenting vertical surfaces 111 and serves
as a ratchet 112 complementary to the piston ratchet 105. The ratchet
plate 107 is restrained against independent rotation within the
bore 92 by operation of a dowel pin 114 and is secured to the crusher
head shaft by means of screws (not shown). A torsion rod 116 of
rectangular configuration in cross-section is secured as by being
welded in the spider cap 41. The torsion rod 116 extends downwardly
through a suitable opening 117 in the retainer washer 97 and through
a rectangular opening 121 in the bottom face of the piston 94 into
the clearance bore 91. As can be seen, the rectangular opening 121
in the bottom face of the piston 94 is sized to give clearance between
all sides thereof and the torsion rod 116 in all vertical positions
of the crusher head shaft 33. While the opening 121 is sized to
give clearance to the torsion rod 116 in all angular positions of
the shaft 33 its size is such that only a limited angular movement
of the piston 94 with the shaft 33 will occur; such movement being
limited by the engagement of the corners of the torsion rod with
the side walls of the opening 121.
Operation of the antispin device 45 will now be given and for this
purpose it is assumed that the crusher 10 is idling with no feed
being supplied. The crusher head shaft 33 will begin to rotate with
the drive eccentric 52. The piston 94 will rotate with the crusher
head shaft 33 for substantially 15.degree. until it is stopped by
the torsion rod 116 which will then be in a diagonal position within
the rectangular opening 121 in the piston 94. The hand or direction
of nonrotation faces of the ratchet teeth are such that when the
crusher head shaft 33 tries to rotate in the same direction as the
drive eccentric 52 the vertical surfaces or teeth 103 and 111 of
the ratchets 105 and 112 respectively, abut to prevent the rotation
of the crusher head shaft 33 with the eccentric 52. Thus, the crusher
head shaft 33 is prevented from spinning even though its vertical
position may be changed.
Assuming now that material is fed into the crusher 10 the crusher
head shaft 33 begins to rotate in the opposite direction with respect
to the direction in which the drive eccentric 52 is rotating. The
piston 94 rotates with the crusher head shaft 33 until the torsion
rod 116 engages the opposite side wall of the rectangular opening
121 in the bottom face of the piston 94. At this point the ratchet
members 105 and 112 will move on their sloping or incline surfaces
102 and 109 respectively, relative to each other allowing rotation
therebetween. Due to the tooth slope or incline the spring 96 will
compress. Thus, as the teeth 103 and 111 move over each other the
piston 94 will rise and fall thus allowing the crusher head shaft
33 to rotate in a direction opposite to the direction of rotation
of the drive eccentric 52.
|