Abstrict In a crusher having a crusher head shaft which is adjustable under
load in the vertical direction and passes through a drive eccentric,
clearance must exist between the shaft and the inner eccentric bearing.
Due to the constantly rotating crushing load which moves angularly
in the same direction as the drive eccentric is rotating and relative
to the shaft which is stationary or slowly rotating in a direction
opposite to the direction in which the drive eccentric is rotating,
the inner race of the inner bearing of the eccentric should be an
interference fit on the shaft. If the inner race is not an interference
fit on the shaft, rapid wear will occur on both the shaft and the
bearing bore. To overcome these two opposing requirements of a loose
fit for adjusting purposes and a tight fit for good bearing practice,
a composite bushing assembly is provided. The assembly includes
a steel bushing and a bronze bushing with the steel bushing having
an interference fit in the bearing race while the bronze bushing
provides the necessary clearance for the vertical adjustment of
the shaft.
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, a crusher head carried
by a shaft which is supported by the frame for rotation about its
own axis, for gyratory movement about the axis of the frame and
for adjustment under load in a vertical direction, a drive eccentric
through which the shaft extends and operable to effect the gyratory
movement of the shaft and crusher head, and having an inner antifriction
bearing which is carried by the drive eccentric for rotatably supporting
the shaft in the drive eccentric;
a bearing assembly interposed between the inner antifriction bearing
and the shaft, said bearing assembly including two separate cylindrical
sleeve members interengaged with each other, substantially over
their entire length, and in concentric relationship, said inner
cylindrical sleeve member being of relatively soft material and
said outer cylindrical sleeve member being of a relatively harder
material, said outer cylindrical sleeve member having an interference
fit with the inner bearing race of the inner antifriction bearing
to prevent relative movement between the bearing assembly and the
inner antifriction bearing inner bearing race due to a rotating
load, said inner cylindrical sleeve member having a clearance fit
with the shaft to permit adjustment of the shaft under load in a
vertical direction; and,
means to supply lubrication to the antifriction elements of the
inner antifriction bearing and to the sliding surfaces present by
said inner cylindrical sleeve member and the shaft;
whereby the shaft is rigidly supported in a radial direction by
operation of the outer cylindrical sleeve member and said outer
cylindrical sleeve member has an interference fit with the inner
race of the inner antifriction bearing, and said inner cylindrical
sleeve member of said bearing assembly provides for a clearance
fit between itself and the shaft to provide for shaft movement under
load in a vertical direction.
2. A gyratory crusher according to claim 1 wherein said outer cylindrical
sleeve member is steel and has an interface fit with the inner bearing
race of said inner antifriction bearing;
said inner cylindrical sleeve member is bronze and constructed
and arranged in concentric relationship within said outer cylindrical
steel sleeve member with a no-clearance fit relationship;
a nut threadedly engaged on the upper end of said outer cylindrical
steel sleeve member and constructed and arranged to abut the upper
axial end face of said inner cylindrical bronze sleeve member and
the upper axial end face of the inner race of the inner antifriction
bearing to effectively secure said sleeve members in operative position.
3. A gyratory crusher according to claim 2 wherein said nut is
formed with a radially inwardly sloping conical surface which operates
to provide a reservoir for lubricating oil;
said nut below said reservoir having a circular wall surface which
is concentric with respect to the shaft and in communication with
said reservoir, the diameter of said circular wall surface being
larger than the diameter of the portion of the shaft around which
it is engaged to form a lubricating flow passage therebetween to
direct lugricant to the joint surface between said bronze bearing
sleeve and the shaft; and,
a plurality of ports formed in the upper portion of said nut, said
ports extending radially inwardly from the outer surface of said
nut into communication with said reservoir, said ports operating
to provide oil flow channels to the exterior of the nut so that
the oil will flow down the exterior of the nut and onto the antifriction
elements of the inner antifriction bearing.
Description BACKGROUND OF THE INVENTION
In a gyratory crusher where the crusher head shaft passes through
a drive eccentric and is adjustable under load in a vertical direction,
clearance must exist between the shaft and the inner race of the
inner bearing of the eccentric. Also, due to the fact that the crushing
load will rotate or more angularly relative to the shaft in the
direction that the drive eccentric rotates, the bearing inner race
should be an interference fit on the shaft. If the inner race is
not an interference fit, rapid wear will occur on both the shaft
and the bearing bore.
SUMMARY OF THE INVENTION
Overcoming the aforementioned requirements of a loose fit for adjustment
purposes and a tight fit for good bearing practice, a composite
bushing assembly is provided. A steel bushing or sleeve in which
a bronze bushing or sleeve is interfitted, the arrangement is such
that the steel bushing has an interference fit with the inner race
of the inner eccentric bearing. The bronze bushing receives the
shaft and the fit therebetween is such as to provide sufficient
clearance to allow for adjustment of the shaft under load in a vertical
direction.
While crushing, the crusher head shaft in a gyratory crusher will
rotate in the opposite direction to that of the shaft drive eccentric.
The speed of this reverse rotation will depend upon the crusher
head diameter and the throw of the drive eccentric. The clearance
between the shaft and the inner bushing or sleeve of the bearing
assembly does not have the same clearance/diameter ratio as the
throw and crusher head diameter. As a result, the shaft will skid
in the inner bushing of the composite bushing assembly. Thus, the
inner bushing or sleeve must be of a material which is suitable
to provide a bearing for rotational as well as vertical sliding
between the shaft and the inner bushing under mixed lubrication
conditions. The outer bushing of the assembly is steel to provide
the rigidity necessary for support.
DESCRIPTION OF THE DRAWING
The drawing shows a view in vertical section through a gyratory
type crusher in which the crusher head shaft is adjusted in a vertical
direction and in which the present invention is incorporated.
DESCRIPTION OF THE INVENTION
Referring to 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 a sealed chamber 21. The closure plate
19 also provides for a hydraulic fluid inlet 22 which communicates
with the 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 midpoint of a bearing
37. The crushing head 24 has a central upwardly tapering bore 26
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 received in an adjustable bearing member 37. A spider 38 bolted
to the top of the frame 11 presents an axial hub 39 the axis of
which is concentric with the axis of the frame. The hub 39 serves
as a housing for an adjustable bearing 37. A cap 41 having an axially
extending sleeve portion 42 is secured to the outer end race of
the hub 39 and locks the outer race of the adjustable bearing 37
in the hub. A crusher head brake 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. To maintain the bearing 55 stationary within the circular
seat 57 the outer race 56 of the bearing has an interference fit
with the circular wall of the bearing seat 57. 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 race 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 circumferential groove or space 69 between
liners 71 and 72 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 formed with the lower portion 18
of the frame hub 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 about the axis of the crusher head shaft
33 slowly in the opposite direction to the eccentric 52 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, in a gyratory crusher having a crusher
head shaft 33 that is adjustable under load in the vertical direction
and which passes through the drive eccentric 52 clearance must
exist between the shaft 33 and the inner race 86 of the inner antifriction
bearing 47 associated with the drive eccentric 52. Also, due to
the condition that the crushing load rotates with the eccentric
52 and in the opposite direction to the slowly rotating shaft 33
when the crusher is under load, the inner race 86 should have an
interference fit on the shaft 33.
To satisfy these two requirements, the bearing assembly 46 is provided.
As shown, the bearing assembly includes a bronze bearing sleeve
87 which is mounted on the reduced lower end 88 of the shaft 33.
In the present instance, the reduced lower end 88 of the shaft 33
is provided with a steel sleeve 89 on which the bronze bearing sleeve
87 is mounted. Interposed between the bronze bearing sleeve 87 and
the inner race 86 of the antifriction bearing 47 is a steel bearing
sleeve 91. The bronze bearing sleeve 87 is concentric within the
steel bearing sleeve and has a no clearance fit therewith. The steel
bearing sleeve 91 has an interference fit with the inner race 86
to provide the desired stiffness to resist the radial loads which
are developed due to the gyratory movement of the drive eccentric
and the crushing load. Also, the interference fit prevents relative
circumferential movement between the sleeve 91 and the bearing inner
race 86. As shown, the steel bearing sleeve at its lower end is
provided with a flange 92. The radially inwardly extending portion
of the flange 92 abuts the lower axial end race of the bronze bearing
sleeve 87 to maintain it in an operative position. The radially
outwardly extending portion of the flange 92 abuts the lower axial
end race of the inner race 86 of bearing 47.
The nut 48 as previously mentioned, is threadedly engaged on the
threaded upper end of the steel bearing sleeve 91 and locks the
entire bearing assembly 46 in operative position.
To provide lubrication to the antifriction bearing 47 and also
to inner surface of the bronze bearing sleeve 87 the nut 48 is
formed with inwardly and downwardly sloping circular surface 94.
The circular surface 94 in cooperation with the upper end of the
steel sleeve 89 serves as an oil reservoir. As can be seen, the
diameter of the inner surface 96 of the nut 48 is greater than the
outer diameter of the sleeve 89. Thus, a circular space 97 is provided
which serves to direct lubricating oil between the bronze bearing
sleeve 87 and the rotating steel sleeve 89. The inner surface of
the bronze bearing sleeve 87 is provided with a plurality of circumferential
oil grooves 98 which capture the oil that passes between the bronze
bearing sleeve 87 and the steel sleeve 89. The oil captured in the
grooves 98 insure that oil to lubricate the sliding surfaces is
available.
To effect positive lubrication of the antifriction elements of
the bearing 47 a plurality of horizontal radially extending ports
101 are formed as by drillng in the nut 48. Thus, lubricating oil
collected in the nut reservoir will flow out through the ports 101
and flow down the sides of the nut falling onto the antifriction
elements of the bearing 47. Lubricating oil is supplied to the interior
of the crusher above the bearing 47 by oil passage 102 and oil pipe
103 which extends inwardly toward the shaft 33 from a dust collar
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