U.S. patent application number 16/062699 was filed with the patent office on 2018-12-27 for torque reaction pulley for an inertia cone crusher.
The applicant listed for this patent is SANDVIK INTELLECTUAL PROPERTY AB. Invention is credited to Magnus FREDRIKSSON, Johan GUNNARSSON, Martin HOLSTEIN, Jonas LINDVALL.
Application Number | 20180369823 16/062699 |
Document ID | / |
Family ID | 55072617 |
Filed Date | 2018-12-27 |
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United States Patent
Application |
20180369823 |
Kind Code |
A1 |
FREDRIKSSON; Magnus ; et
al. |
December 27, 2018 |
TORQUE REACTION PULLEY FOR AN INERTIA CONE CRUSHER
Abstract
A torque reaction pulley for an inertia cone crusher having an
elastically deformable component responsive to a change in torque
through the drive transmission of the crusher due to rotation of an
unbalanced weight within the crusher.
Inventors: |
FREDRIKSSON; Magnus; (Dalby,
SE) ; HOLSTEIN; Martin; (Limhamn, SE) ;
GUNNARSSON; Johan; (Sovde, SE) ; LINDVALL; Jonas;
(Lund, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SANDVIK INTELLECTUAL PROPERTY AB |
Sandviken |
|
SE |
|
|
Family ID: |
55072617 |
Appl. No.: |
16/062699 |
Filed: |
December 18, 2015 |
PCT Filed: |
December 18, 2015 |
PCT NO: |
PCT/EP2015/080433 |
371 Date: |
June 15, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B02C 2/042 20130101;
F16H 2055/366 20130101; F16F 15/1201 20130101; F16H 55/36
20130101 |
International
Class: |
B02C 2/04 20060101
B02C002/04; F16H 55/36 20060101 F16H055/36; F16F 15/12 20060101
F16F015/12 |
Claims
1. A torque reaction pulley mountable at an inertia crusher to form
part of a drive transmission mechanism for rotational drive of an
unbalanced mass body within the crusher, the pulley comprising: a
drive input portion connectable to a motor to provide rotational
drive to the pulley; a drive output portion connectable to the mass
body to transmit the rotational drive to the mass body; and an
elastic component formed non-integrally with the drive input and
output portions and having a first part anchored in coupled
connection with the drive input portion and a second part anchored
in coupled connection with the drive output portion so as to be
positioned in the drive transmission pathway intermediate the drive
input and output portions, the elastic component being configured
to transmit a torque to the mass body and to dynamically displace
and/or deform elastically in response to a change in the torque
resultant from rotation of the mass body within the crusher so as
to dissipate the change in the torque at the crusher.
2. The pulley as claimed in claim 1, wherein the elastic component
is attached to the drive input and output portions via releasable
attachments such that the elastic component may be mounted and
decoupled from the drive input and output portions.
3. The pulley as claimed in claim 1, wherein the elastic component
is mounted at one end of the pulley.
4. The pulley as claimed in claim 2, wherein at least parts of the
attachments are positioned externally at the pulley.
5. The pulley as claimed in claim 1, wherein the elastic component
is connected indirectly to the drive output portion via at least
one drive component forming a part of the pulley and configured to
transmit the torque.
6. The pulley as claimed in claim 1, wherein the elastic component
is connected indirectly to the drive input portion via at least one
drive component forming a part of the pulley and configured to
transmit the torque.
7. The pulley as claimed in claim 1, wherein the drive input
portion includes an annular belt support component arranged to
mount and positionally support a belt drive to extend at least
partially around the belt support component.
8. The pulley as claimed in claim 1, wherein the drive output
portion includes a race having an internally extending socket
capable of mounting one end of a torsion bar or drive shaft
demountably connectable to the pulley.
9. The pulley as claimed in claim 1, further comprising a first
adaptor flange coupled between and connecting the drive input
portion and the elastic component.
10. The pulley as claimed in claim 9, further comprising a second
adaptor flange coupled between and connecting the drive output
portion and the elastic component.
11. The pulley as claimed in claim 10, further comprising an
adaptor shaft extending between and connecting the second adaptor
flange and the drive output portion.
12. The pulley as claimed in claim 1, wherein the elastic component
includes at least one elastomeric component configured to twist in
response to the transmission of the torque through the pulley.
13. The pulley as claimed in claim 1, wherein the elastic component
at least one disc having spokes configured to deform via twisting
about a rotational axis of the pulley in response to transmission
of the torque through the pulley.
14. The pulley as claimed in claim 13, further comprising a
plurality of discs stacked on top of one another via
interconnecting members such that the spokes are arranged in series
and/or in parallel in the drive transmission pathway intermediate
to the drive input and output portions.
15. An inertia cone crusher comprising the pulley of claim 1.
Description
FIELD OF INVENTION
[0001] The present invention relates to a torque reaction pulley
positionable within the drive transmission of an inertia cone
crusher and in particular, although not exclusively, to a torque
reaction pulley configured to dissipate changes in torque created
by the rotation of an unbalanced mass body within the crusher.
BACKGROUND ART
[0002] Inertia cone crushers are used for the crushing of material,
such as stone, ore etc., into smaller sizes. The material is
crushed within a crushing chamber defined between an outer crushing
shell (commonly referred to as the concave) which is mounted at a
frame, and an inner crushing shell (commonly referred to as the
mantle) which is mounted on a crushing head. The crushing head is
typically mounted on a main shaft that mounts an unbalance weight
via a linear bushing at an opposite axial end. The unbalance weight
(referred to herein as an unbalanced mass body) is supported on a
cylindrical sleeve that is fitted over the lower axial end of the
main shaft via an intermediate bushing that allows rotation of the
unbalance weight about the shaft. The cylindrical sleeve is
connected, via a drive transmission, to a pulley which in turn is
drivably connected to a motor operative for rotating the pulley and
accordingly the cylindrical sleeve. Such rotation causes the
unbalance weight to rotate about the a central axis of the main
shaft, causing the main shaft, the crushing head and the inner
crushing shell to gyrate and to crush material fed to the crushing
chamber. Example inertia cone crushers are described in EP 1839753;
U.S. Pat. No. 7,954,735; U.S. Pat. No. 8,800,904; EP 2535111; EP
2535112; US 2011/0155834.
[0003] However, conventional inertia crushers whilst potentially
providing performance advantages over eccentric gyratory crushers,
are susceptible to accelerated wear and unexpected failure due to
the high dynamic performance and complicated force transmission
mechanisms resulting from the unbalanced weight rotating around the
central axis of the crusher. In particular, the drive mechanism
that creates the gyroscopic precision of the unbalanced weight is
exposed to exaggerated dynamic forces and accordingly component
parts are susceptible to wear and fatigue. Current inertia cone
crushers therefore may be regarded as high maintenance apparatus
which is a particular disadvantage where such crushers are
positioned within extended material processing lines.
SUMMARY OF THE INVENTION
[0004] It is an objective of the present invention to provide a
drive transmission coupling mountable at an inertia crusher to form
part of a drive transmission mechanism for rotational drive of an
unbalanced weight being configured to dissipate relatively large
dynamic torque induced by the unbalanced weight gyrating within the
crusher and to prevent the transmission of such torque to the
crusher and in particular those components of the drive
transmission.
[0005] It is a further specific objective to provide an inertia
crusher drive transmission coupling configured to deflect and/or
dissipate mechanical loading torque associated with the oscillating
movement of the unbalanced weight that would otherwise lead to
accelerated wear, damage and failure of component parts of the
drive transmission and/or the crusher generally.
[0006] The objectives are achieved by a drive transmission coupling
in the form of a pulley compatible with a drive transmission
arrangement or mechanism of an inertia cone crusher that, in part,
isolates the rotating unbalanced weight and in particular the
associated dynamic forces (principally torque) created during
operation of the crusher from at least some components or parts of
components of the upstream drive transmission being responsible to
induce the rotation of the unbalanced mass body. In particular, the
present drive pulley comprises a torque reaction elastic component
configured to receive changes in the torque at the drive
transmission (referred to herein as a `reaction torque`) created by
the unbalanced weight as it is rotated about a gyration axis and to
supress, dampen, dissipate or diffuse the reaction torque and
inhibit or prevent direct transmission into at least regions of the
drive transmission components.
[0007] The reaction torque pulley is advantageous to support the
mass body in a `floating` arrangement within the crusher and to
allow and accommodate non-circular orbiting motion of the crusher
head (and hence main shaft) about the gyration axis causing in turn
the unbalanced weight to deviate from its ideal circular rotational
path. Accordingly the drive transmission components are partitioned
from the torque resultant from undesired changes in the angular
velocity of the unbalanced weight and/or changes in the radial
separation of the main shaft and the centre of mass of the
unbalanced weight from the gyration axis. Accordingly, the drive
transmission, incorporating the present torque reaction component,
is isolated from exaggerated and undesirable torque resulting from
the non-ideal, dynamic and uncontrolled movement of the oscillating
mass body. The torque reaction coupling is configured to receive,
store and dissipate energy received from the motion of the rotating
mass body and to, in part, return at least some of this torque to
the mass body as the reactive coupling displaces and/or deforms
elastically in position within the drive transmission pathway. Such
an arrangement is advantageous to reduce and to counter the large
exaggerated torque so as to facilitate maintenance of a desired
circular rotational path and angular velocity of the unbalanced
mass about the gyration axis.
[0008] The present torque reaction pulley provides a flexible or
non-rigid connection to the unbalanced weight to allow at least
partial independent movement (or movement freedom) of the
unbalanced weight relative to at least parts of the drive
transmission such that the drive transmission has movement freedom
to accommodate dynamic torsional change. In particular, the centre
of mass of unbalanced weight is free to deviate from a
predetermined (or ideal) circular gyroscopic precession and angular
velocity without compromising the integrity of the drive
transmission and other components within the crusher. The present
pulley is advantageous to prevent damage and premature failure of
the crusher component parts and in particular those parts
associated with the drive transmission.
[0009] According to a first aspect of the present invention there
is provided a torque reaction pulley mountable at an inertia
crusher to form part of a drive transmission mechanism for
rotational drive of an unbalanced mass body within the crusher
comprising a drive input portion connectable to a motor to provide
rotational drive to the pulley; a drive output portion connectable
to the mass body to transmit the rotational drive to the mass body;
an elastic component formed non-integrally with the input and
output portions and having a first part anchored in coupled
connection with the drive input portion and a second part anchored
in coupled connection with the drive output portion so as to be
positioned in the drive transmission pathway intermediate the drive
input and output portions; the elastic component configured to
transmit a torque to the mass body and to dynamically displace
and/or deform elastically in response to a change in the torque
resultant from rotation of the mass body within the crusher so as
to dissipate the change in the torque at the crusher.
[0010] The torque reaction pulley is configured to deflect and/or
dissipate exclusively mechanical loading torque associated with the
oscillating movement of the unbalanced weight (due to deviation of
the main shaft form the ideal circular path) within the drive
transmission, the drive input component or the mass body. That is,
the torque reaction pulley is positioned and/or configured to
respond exclusively to torsional change and to be unaffected by
other transverse loading including in particular tensile,
compressive, shear and frictional forces within the drive
transmission. Reference within the specification to `a torque
reaction pulley` encompasses a wheel drive transmission positioned
as a drive input component downstream (in the drive transmission
pathway) of a drive belt (such as V-belts), a motor drive shaft, a
motor or other power source unit, component or arrangement
positioned upstream from the crusher.
[0011] Reference within this specification to the elastic component
being configured to `displace and/or deform elastically`
encompasses the elastic component configured to move relative to
other components within the drive transmission and/or the other
components or regions of the torque reaction pulley and to displace
relative to a `normal` operation position of the elastic component
when transmitting driving torque to the mass body at a
predetermined torque magnitude without influence or change in the
torque resultant from changes in rotational motion of the crusher
head about the gyration axis (e.g., a change in the tilt angle of
the crusher head) and/or a rotational speed of the crusher head.
This term encompasses the elastic component comprising a stiffness
sufficient to transmit a drive torque to at least part of the mass
body whilst being sufficiently responsive by movement/deformation
in response to change in the torque at the drive transmission, the
mass body or drive input component. The term `dynamically displace`
encompasses rotational movement and translational shifting of the
torque reaction coupling in response to the deviation of the main
shaft from the circular orbiting path.
[0012] Preferably, the torque reaction coupling is mechanically
attached, anchored or otherwise linked to the drive transmission,
and in particular other components associated with the rotation
drive imparted to the crusher head, and comprises at least a part
or region that is configured to rotate or twist about an axis so as
to absorb the changes in torque. Preferably, at least respective
first and second attachment ends or regions of the torque reaction
coupling are mechanically fixed or coupled to components within the
drive transmission such that at least a further part or region of
the torque reaction coupling (positionally intermediate the first
and second attachment ends or regions) is configured to rotate or
twist relative to (and independently of) the static first and
second attachment ends or regions.
[0013] The term `change in rotational motion of the crusher head`
encompasses deviation of the crusher head, from a desired circular
orbiting path about the gyration axis. Where the crusher head is
inclined at a tilt angle, the change in rotational motion of the
crusher head may comprise a change in the tilt angle. Optionally,
the crusher head may be aligned parallel with a longitudinal axis
of the crusher such that the deviation from the circular orbiting
path is a translational displacement. The reference herein to a
`change in the rotational speed of the crusher head` encompasses
sudden changes in angular velocity of the head and accordingly the
mass body that in turn results in inertia changes within the system
that are transmitted through the drive transmission and manifest as
torque.
[0014] Optionally, the torque reaction pulley is positioned
immediately below the crusher and represents an end drive
transmission component of the crusher positioned downstream of a
drive input arrangement such as a belt drive. Optionally, the
torque reaction coupling is aligned so as to be positioned on the
longitudinal axis extending through the crusher head and/or main
shaft when the crusher is non-operative or immobile. Preferably,
the torque reaction coupling is positioned on the central
longitudinal axis of the crusher such that the axis of the pulley
is coaxial with the crusher longitudinal axis.
[0015] Preferably, the elastic component is attached to the drive
input and output portions of the torque reaction pulley via
releasable attachments such that the elastic component may be
mounted and decoupled from the drive input and output portions and
hence the crusher. The releasable attachments may comprise bolts,
screws, pins, clips, cooperating threads, push-fit or snap-fit
connections to allow releasable mounting of the elastic component
at the pulley.
[0016] Preferably the elastic component is mounted at one end of
the pulley. Preferably, the elastic component is mounted at a lower
end of the pulley when the pulley is secured in position at the
crusher. Preferably, the releasable attachments that connect the
elastic component to the pulley are accessible from below the
pulley to facilitate mounting and demounting of the elastic
component during servicing, maintenance or to change the torque
reaction characteristic of the pulley. In particular, and
preferably at least parts of the attachments are positioned
externally at the pulley.
[0017] Optionally, the drive transmission within which the present
torque reaction pulley is positioned comprises at least one further
drive transmission component coupled between the mass body and the
drive input component to form part of the drive transmission.
Optionally, the further drive transmission component may comprise a
torsion rod, drive shaft, bearing assembly, bearing race, torsion
bar mounting socket or bushing connecting the unbalanced weight to
a power unit such as a motor.
[0018] Optionally, the torque reaction pulley comprises a modular
assembly construction formed from a plurality of component parts in
which a selection of the component parts are configured to move
relative to one another.
[0019] Optionally, the elastic component is connected indirectly to
the output portion via at least one drive component forming a part
of the pulley and configured to transmit the torque.
[0020] Optionally, the elastic component is connected indirectly to
the input portion via at least one drive component forming a part
of the pulley and configured to transmit the torque. The drive
component may comprise bearings, bearing housings, adaptor shafts,
flanges, bearing races or other annular bodies or linkages that
form a modular component part of the pulley coupling adjacent
components.
[0021] Preferably the drive input portion comprises an annular belt
support component to mount and positionally support a belt drive to
extend at least partially around the belt support component.
Preferably, the belt support comprises a plurality of grooves
extending circumferentially around the support and recessed into an
external facing surface of the support with each groove configured
to at least partially accommodate a V-belt drive component.
Preferably, the grooves comprises a V-shaped cross-sectional
profile and extend 360.degree. around the belt support.
[0022] Preferably the drive output portion comprise a race having
an axially extending socket or recess capable of mounting one end
of a torsion bar or drive shaft demountably connectable to the
pulley. The race preferably comprises a plurality of bores
extending internally through at least part of the body of the race
to receive attachment bolts to releasably mount the elastic
component to the race.
[0023] Optionally, the pulley comprises a first adaptor flange
coupled between and connecting the input portion and the elastic
component. Optionally, the pulley further comprises a second
adaptor flange coupled between and connecting the output portion
and the elastic component. Preferably, the first and second adaptor
flanges are resiliently deformable. Preferably, the adaptor flanges
are annular and comprise respective elastomeric rings.
[0024] Preferably, the elastic component comprises at least one
elastomeric component configured to twist in response to the
transmission of the torque through the pulley. Such a configuration
is advantageous as the elastic component is configured to deform in
response to a change in torque through the pulley and to return
elastically to the shape, configuration and position of the
component prior to the change in torque.
[0025] Optionally, the elastic component comprises at least one
disc having spokes configured to deform via twisting about a
rotational axis of the pulley in response to transmission of the
torque through the pulley. Preferably, the elastic component
comprises a plurality of discs stacked on top of one another via
interconnecting members such that the spokes are arranged in series
in the drive transmission pathway intermediate to the drive input
and output portions.
[0026] Optionally, at least some of the discs of the stack may be
connected axially to adjacent discs via connections positioned
towards the radial perimeter of the discs and at least some of the
discs of the stack may be connected axially to adjacent discs via
mountings positioned at radially inner regions of the discs.
Optionally, the stack of discs may comprise a first attachment
plate secured to an upper disc at an upper end of the stack and a
corresponding second attachment plate secured to a lower disc at a
lower end of the stack. Optionally, the discs may be secured to one
another via bolts, pins or lugs at either the radially outer or
inner portions.
[0027] Optionally, the elastic component comprises a spring.
Optionally, the spring is a helical or coil spring. Optionally, the
spring comprises any one or a combination of the following: a
torsion spring, a coil spring, a helical spring, a gas spring, a
torsion disc spring, or a compression spring. Optionally, the
spring comprises any cross-sectional shape profile including for
example rectangular, square, circular, oval etc. Optionally the
spring may be formed from an elongate metal strip coiled into a
circular spiral.
[0028] Optionally, the elastic component comprises a torsion bar,
pad or body configured to twist about a central axis in response to
differences in torque at each respective end of the elastic
component.
[0029] Optionally, the torque reaction pulley comprises a plurality
of elastic components such as springs of different types or
configurations and/or elastomers mounted at the pulley in series
and/or in parallel.
[0030] Optionally, the spring comprises a stiffness in range 100
Nm/degrees to 1500 Nm/degrees. Optionally, the spring comprises a
damping coefficient (in Nms/degree) of less than 10%, 5%, 3%, 1%,
0.5% or 0.1% of the stiffness depending on the power of the crusher
motor and the mass of the unbalanced weight. Such an arrangement is
advantageous to enable the spring to transmit a drive torque whilst
being sufficiently flexible to deform in response to the reaction
torque. In particular, the elastic component(s) may be configured
to twist between respective connection ends by an angle in the
range +/-45.degree.. Accordingly, the elastic reaction coupling is
configured to twist internally (with reference to its connection
ends) by an angle up to 90.degree. in both directions. Such a range
of twist excludes an initial deflection due to torque loading when
the crusher is operational and the flexible coupling is acted upon
by the drive torque. Such initial preloading may involve the
coupling deflecting by 10 to 50.degree., 10 to 40.degree., 10 to
30.degree., 10 to 25.degree., 15 to 20.degree. or 20 to 30.degree..
Advantageously, the elastic coupling is capable of deflecting
further beyond the initial torsional preloading so as to be capable
of `winding` or `unwinding` from the initial (e.g., 15 to
20.degree.) deflection. Optionally, the torsion responsive coupling
comprises a maximum deflection, that may be expressed as a twist of
up to 70.degree., 80.degree., 90.degree., 100.degree., 110.degree.,
120.degree., 130.degree. or 140.degree. in both directions.
Optionally, the coupling may be configured to deflect by 5 to 50%,
5 to 40%, 5 to 30%, 5 to 20%, 5 to 10%, 10 to 40%, 20 to 40%, 30 to
40%, 20 to 40%, 20 to 30%, 10 to 50%, 10 to 30% or 10 to 20% of the
maximum deflection in response to the `normal` loading torque
transmitted through the coupling when the crusher is active
optionally pre or during crushing operation.
[0031] The deviations from the circular orbiting path of the mass
body may accordingly result from deviations by the crusher head
from the desired circular rotational path that, in turn, may result
from changes in the type, flow rate or volume of material within
the crushing zone (between the crushing shells) and/or the shape
and in particular imperfections or wear of mantle and concave.
[0032] According to a second aspect of the present invention there
is provided an inertia cone crusher comprising a pulley as claimed
herein.
[0033] According to a third aspect of the present invention there
is provided an inertia crusher comprising: a frame to support an
outer crushing shell; a crusher head moveably mounted relative to
the frame to support an inner crushing shell to define a crushing
zone between the outer and inner crushing shells; a drive
transmission mechanism as described herein and a torque reaction
pulley as described and claimed herein.
[0034] The present torque reaction pulley is advantageous to be
dynamically responsive to changes in the rotational path and/or the
angular velocity of the mass body and in particular a change in the
rotational motion of the crusher head about the gyration axis
and/or a rotational speed of the crusher head. This in turn causes
the change in torque within the drive transmission. The present
torque reaction pulley therefore provides a flexible linkage to
accommodate undesired and unpredicted torsion created by rotation
of the mass body.
BRIEF DESCRIPTION OF DRAWINGS
[0035] A specific implementation of the present invention will now
be described, by way of example only, and with reference to the
accompanying drawings in which:
[0036] FIG. 1 is a cross-sectional view through an inertia cone
crusher according to one specific implementation of the present
invention;
[0037] FIG. 2 is a schematic side view of selected moving
components within the inertia crusher of FIG. 1 including in
particular a crushing head, an unbalanced weight and a drive
transmission;
[0038] FIG. 3 is a cross-sectional perspective view of a torque
reaction pulley being a drive input component of the crusher of
FIG. 1;
[0039] FIG. 4 is a further cross-sectional view of the pulley of
FIG. 3;
[0040] FIG. 5 is a cross-sectional perspective view of a further
specific implementation of an elastically deformable component
forming a part of a drive input pulley;
[0041] FIG. 6 is a further cross-sectional perspective view of a
region of the elastically deformable component of FIG. 5.
[0042] FIG. 7 is a further specific implementation of a torque
reaction pulley having an elastically deformable component
positioned between selected drive transmission components within
the pulley.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION
[0043] FIG. 1 illustrates an inertia cone crusher 1 in accordance
with one embodiment of the present invention. The inertia crusher 1
comprises a crusher frame 2 in which the various parts of the
crusher 1 are mounted. Frame 2 comprises an upper frame portion 4,
and a lower frame portion 6. Upper frame portion 4 has the shape of
a bowl and is provided with an outer thread 8, which cooperates
with an inner thread 10 of lower frame portion 6. Upper frame
portion 4 supports, on the inside thereof, a concave 12 which is a
wear part and is typically cast from a manganese steel.
[0044] Lower frame portion 6 supports an inner crushing shell
arrangement represented generally by reference 14. Inner shell
arrangement 14 comprises a crushing head 16, having a generally
coned shape profile and which supports a mantle 18 that is
similarly a wear part and typically cast from a manganese steel.
Crushing head 16 is supported on a part-spherical bearing 20, which
is supported in turn on an inner cylindrical portion 22 of lower
frame portion 6. The outer and inner crushing shells 12, 18 form
between them a crushing chamber 48, to which material that is to be
crushed is supplied from a hopper 46. The discharge opening of the
crushing chamber 48, and thereby the crushing performance can be
adjusted by means of turning the upper frame portion 4, by means of
the threads 8,10, such that the vertical distance between the
shells 12, 18 is adjusted. Crusher 1 is suspended on cushions 45 to
dampen vibrations occurring during the crushing action.
[0045] The crushing head 16 is mounted at or towards an upper end
of a main shaft 24. An opposite lower end of shaft 24 is encircled
by a bushing 26, which has the form of a cylindrical sleeve.
Bushing 26 is provided with an inner cylindrical bearing 28 making
it possible for the bushing 26 to rotate relative to the crushing
head shaft 24 about an axis S extending through head 16 and shaft
24.
[0046] An unbalance weight 30 is mounted eccentrically at (one side
of) bushing 26. At its lower end, bushing 26 is connected to the
upper end of a drive transmission mechanism indicated generally by
reference 55. Drive transmission 55 comprises a first upper torsion
bar 5 having a first upper end 7 and a second lower end 9. The
first end 7 is connected to a lowermost end of bushing 26 via a
race 31 whilst second end 9 is mounted in coupled arrangement with
a drive shaft 36 rotatably mounted at frame 6 via a bearing housing
35. A second lower torsion bar 37 is drivably coupled to a lower
end of drive shaft 36 via its first upper end 39. A corresponding
second lower end 38 of second torsion bar 37 is mounted at a drive
pulley indicated generally by reference 42. An upper balanced
weight 23 is mounted to an axial upper region of drive shaft 36 and
a lower balanced weight 25 is similarly mounted at an axial lower
region to drive shaft 36. According to the specific implementation,
drive shaft 36, bearing housing 35, first and second torsion bars
5, 37 and pulley 42 are aligned coaxially with one another, main
shaft 24 and crushing head 16 so as to be centred on axis S. Drive
pulley 42 mounts a plurality of drive V-belts 41 extending around a
corresponding motor pulley 43. Pulley 42 is driven by a suitable
electric motor 44 controlled via a control unit 47 that is
configured to control the operation of the crusher 1 and is
connected to the motor 44, for controlling the RPM of the motor 44
(and hence its power). A frequency converter, for driving the motor
44, may be connected between the electric power supply line and the
motor 44. Pulley 42 comprises a torque reaction coupling indicated
generally by reference 32 having at least one component being
configured to deform and/or displace elastically in response to
changes torque changes as described in detail below.
[0047] According to the specific implementation, drive mechanism 55
comprises four CV joints at the regions of the respective mounting
ends 7 and 9 of the first torsion bar 5 and the respective ends 39,
38 of the second torsion bar 37. Accordingly, the rotational drive
of the pulley 42 by motor 44 is translated to bushing 26 and
ultimately unbalanced weight 30 via intermediate drive transmission
components 5, 36 and 37. Accordingly, pulley 42 may be regarded as
a drive input component of crusher 1. Pulley 42 is centred on a
generally vertically extending central axis C of crusher 1 that is
aligned coaxially with shaft and head axis S when the crusher 1 is
stationary.
[0048] When the crusher 1 is operative, the drive transmission
components 5, 36, 37 and 42 are rotated by motor 44 to induce
rotation of bushing 26. Accordingly, bushing 26 swings radially
outward in the direction of the unbalance weight 30, displacing the
unbalance weight 30 away from crusher vertical reference axis C in
response to the centrifugal force to which the unbalance weight 30
is exposed. Such displacement of the unbalance weight 30 and
bushing 26 (to which the unbalance weight 30 is attached), is
achieved due to the motional freedom of the CV joints at the
various regions of drive transmission 55. Additionally, the desired
radial displacement of weight 30 is accommodated as the
sleeve-shaped bushing 26 is configured to slide axially on the main
shaft 24 via cylindrical bearing 28. The combined rotation and
swinging of the unbalance weight 30 results in an inclination of
the main shaft 24, and causes head and shaft axis S to gyrate about
the vertical reference axis C as illustrated in FIG. 2 such that
material within crushing chamber 48 is crushed between outer and
inner crushing shells 12, 18. Accordingly, under normal operating
conditions, a gyration axis G, about which crushing head 16 and
shaft 24 will gyrate, coincides with the vertical reference axis
C.
[0049] FIG. 2 illustrates the gyrating motion of the central axis S
of the shaft 24 and head 16 about the gyration axis G during normal
operation of the crusher 1. For reasons of clarity, only the
rotating parts are illustrated schematically. As the drive shaft 36
and torsion rods 5 and 37 are rotated by the induced rotation of
drive input pulley 42, the unbalance weight 30 swings radially
outward thereby tilting the central axis S of the crushing head 16
and the shaft 24 relative to the vertical reference axis C by an
inclination angle i. As the tilted central axis S is rotated by the
drive shaft 36, it will follow a gyrating motion about the gyration
axis G, the central axis S thereby acting as a generatrix
generating two cones meeting at an apex 13. A tilt angle .alpha.,
formed at the apex 13 by the central axis S of head 16 and the
gyration axis G, will vary depending on the mass of the unbalance
weight 30, the RPM at which the unbalance weight 30 is rotated, the
type and amount of material that is to be crushed, the DO setting
and the shape profile of the mantle and concave 18, 12. For
example, the faster the drive shaft 36 rotates, the more the
unbalance weight 30 will tilt the central axis S of the head 16 and
the shaft 24. Under the normal operating conditions illustrated in
FIG. 2, the instantaneous inclination angle i of the head 16
relative to the vertical axis C coincides with the apex tilt angle
.alpha. of the gyrating motion. In particular, when the drive
transmission components 5, 36, 37 and 42 are rotated the unbalanced
weight 30 is rotated such that the crushing head 16 gyrates against
the material to be crushed within the crushing chamber 48. As the
crushing head 16 rolls against the material at a distance from the
periphery of the outer crushing shell 12, central axis S of
crushing head 16, about which axis the crushing head 16 rotates,
will follow a circular path about the gyration axis G. Under normal
operating conditions the gyration axis G coincides with the
vertical reference axis C. During a complete revolution, the
central axis S of the crushing head 16 passes from 0-360.degree.,
at a uniform speed, and at a static distance from the vertical
reference axis C.
[0050] However, the desired circular gyroscopic precession of head
16 about axis C is regularly disrupted due to many factors
including for example the type, volume and non-uniform delivery
speed of material within the crushing chamber 48. Additionally,
asymmetric shape variation of the crushing shells 12, 18 acts to
deflect axis S (and hence the head 16 and unbalanced weight 30)
from the intended inclined tilt angle i. Sudden changes from the
intended rotational path of the main shaft relative to axis G and
speed of the unbalanced weight 30 manifest as substantial
exaggerated dynamic torsional changes that are transmitted into the
drive transmission components 5, 36, 37 and 42. Such dynamic torque
can result in accelerated wear, fatigue and failure of the drive
transmission 55 and indeed other components of the crusher 1.
[0051] Torque reaction coupling 32, comprises at least one elastic
component configured to deform elastically in response to receipt
of the dynamic torque resultant from the undesired and uncontrolled
movement and speed of unbalanced weight 30. In particular, coupling
32 is adapted to be self-adjusting via twisting, radial and/or
axial expansion and contraction as torque is transmitted through
the transmission 55. Accordingly, the reaction torque resultant
from the exaggerated motion of unbalanced weight 30 is dissipated
by coupling 32 and is inhibited and indeed prevented from
propagation within the drive transmission 55. Torque reaction
coupling 32 is configured to receive, store and at least partially
return torque to components of the drive transmission 55 such as in
particular bushing 26 and unbalanced weight 30. Accordingly,
unbalanced weight 30 via coupling 32 is suspended in a `floating`
arrangement relative to parts of the drive transmission 55. That
is, coupling 32 enables a predetermined amount of change in the
tilt angle i of weight 30 in addition to changes in the angular
velocity of weight 30 relative to the corresponding rotational
drive of components 36, 37 and 42
[0052] Referring to FIGS. 3 and 4, the drive pulley 42 comprises a
radially outermost race 69 having a series of grooves 51 to
partially accommodate the V-belts 41 (FIG. 1) configured to drive
rotation of race 69. A radially inner race 67 defines a socket 68
to receive the lower end 38 of lower torsion bar 37. An inner
bearing assembly, comprising bearings 70 and bearing raceways 71,
is mounted radially outside inner race 67 and secured in position
via an upper mounting disc 73 and a lower mounting disc 74. An
adaptor shaft indicated generally by reference 81 comprises a
radially outward extending axially upper cup portion 84
non-moveably attached to a lower region 83 of inner race 67.
Adaptor shaft 81 also comprises a radially outward extending flange
85 provided at a lowermost end of shaft 81. An outer bearing
assembly, comprising bearings 88 and bearing raceways 87, is
positioned radially between the grooved radially outer race 69 and
a bearing housing 72 that is positioned radially between the two
bearings assemblies 87, 88 and 70, 71. Accordingly, the outer
grooved race 69 is capable of independent rotation relative to the
inner race 67 via the respective bearing assemblies 70, 71 and 87,
88.
[0053] The flexible torsion coupling 32 is positioned in the drive
transmission pathway between the grooved pulley race 69 and the
inner race 67 via adaptor shaft 81. According to the specific
implementation, coupling 32 comprises a modular assembly formed
from deformable elastomeric rings and a set of intermediate metal
disc springs. In particular, a first annular upper elastomer ring
78 mounts at its lowermost annular face a first half of a disc
spring 79. A corresponding second lower annular elastomer ring 77
similarly mounts at its upper annular face a second half of the
disc spring 80 to form an axially stacked assembly in which the
metal disc spring 79, 80 separates respective upper and lower
elastomeric rings 78, 77. Rings 78, 77 are formed from a relatively
soft elastomeric material that is deformed and in particular
twisted internally (by around 15 to 20.degree.) during an initial
preloading of the crusher when motor is operational and torque is
transmitted through the coupling 32. A first upper annular metal
flange 76 is mounted at an upper annular face of the upper
elastomer ring 78 and a corresponding second lower metal flange 89
is attached to a corresponding axially lower face of the lower
elastomer ring 77. Upper flange 76 is attached at its radially
outer perimeter to a first upper adaptor flange 75 formed as a thin
plate of a steel material. Flange 75 is secured at its radially
outer perimeter to a lower annular face of the grooved belt race
69. Accordingly, adaptor flange 75 and coupling flange 76 provide
one half of a mechanical coupling between the grooved V belt race
69 and the flexible coupling 32. Similarly, a second lower adaptor
flange 82, (also formed from as a thin plate of a steel material)
is mounted to the lower coupling flange 89 at a radially outer
region and is mounted to adaptor shaft flange 85 at a radially
inner region. Accordingly, adaptor flange 82 provides a second half
of the mechanical connection between flexible coupling 32 and inner
race 67 (via adaptor shaft 81). Each of the elastomeric components
78 and 77 are configured to elastically deform in response to
torsional loading in a first rotational direction due to the drive
torque and in the opposed rotational direction by the reaction
torque. Adaptor flanges 75 and 82 are specifically configured
physically and mechanically to be stiffer in torsion relative to
components 77, 78, but to be deformable axially so as to provide
axial freedom and to allow components 78, 77 to flex in response to
the torque loading.
[0054] Flexible coupling 32 is demountably interchangeable at
pulley 42 via a set of releasable connections. In particular, upper
coupling flange 76 is releasably mounted to adaptor flange 75 via
attachments bolts 97 and lower coupling flange 89 is releasably
attached to adaptor flange 82 via corresponding attachment bolts
50. Similarly, adaptor flange 75 is releasably mounted to outer
race 69 via a set of attachment bolts 52. Additionally, lower
adaptor flange 82 is releasably attached to the adaptor shaft
flange 85 via releasable attachment bolts 98.
[0055] Adaptor shaft 81 is interchangeably mounted at race lower
region 83 via a set of attachment threaded bolts 53 received with
threaded bores 106 extending axially into race 67 from lower region
83. Accordingly, coupling 32 is interchangeable (mountable and
demountable) at pulley 42 via some or all of the releasable
attachment components 52, 97, 50, 98 and 53. Such a configuration
is advantageous to selectively adjust the torque reaction
characteristic of pulley 42 as desired to suit for example
different types of material to be processed, different material
feed flow rates, the status and integrity of the inner and outer
crushing shells 18, 12 and the speed or power drawer of the motor
that drives the drive transmission 55. Additionally, the material
of elastomeric rings 77, 78 and flanges 75 and 82 may be selected
to achieve the desired deformation characteristic with regard to
the annular range of twist of coupling 32 and the axial
displacement provided by flange 82.
[0056] In the mounted position at pulley 42, the elastomeric
components 78, 77 (in addition to the metal disc spring 79, 80) are
configured to deform radially and axially via twisting, axial and
radial compression and expansion in response to the driving and
reaction torques. Coupling 32, is accordingly configured to
dissipate the undesired reaction torque created by the change in
the tilt angle .alpha. and the non-circular orbiting motion of the
unbalanced weight 30. In particular, coupling 32 is configured
specifically to absorb and dissipate torque.
[0057] FIGS. 5 to 6 illustrate further embodiments of torque
reaction coupling 32 forming a component part of pulley 42.
According to the further embodiment of FIGS. 5 and 6, the elastic
deformation is provided by a plurality of radially extending spokes
58 that are capable of distorting and deflecting in a
circumferential direction (by rotation) and hence to respond to the
change in torque induced by the motion of unbalanced weight 30.
Each spoke is separated circumferentially and radially from
neighbouring spokes 58 by gap regions 104 that allow each spoke 58
to flex in the circumferential and radial directions. In
particular, coupling 32 comprises a stack 54 of metal discs 60 that
each comprises a radially outermost perimeter region 56 and a
radially innermost region 57. Spokes 58 extend between regions 56
and 57 with each spoke extending along a segment of a spiral having
a generally arcuate curved shape profile. Each spoke 58 extends
radially inward from a perimeter collar 105 and is terminated at
its radially innermost end by a mounting hub 101. A plurality of
mounting flanges 59 project radially outward from outer collar 105
of an uppermost disc 60 of the stack 54. It is noted that only a
portion of the stack 54 is illustrated and a corresponding
lowermost disc (not shown) of the stack comprises corresponding
flanges 59.
[0058] Each of the discs 60 are arranged in pairs in the axial
direction with neighbouring discs of a pair each connected
outwardly towards perimeter region 56 or innermost region 57. A
polarity of bores 99 extend through each collar 105 with an
attachment bolt 100 coupling two discs 60 of a pair. The discs 60
of a corresponding adjacent pair of the stack 54 are coupled at
respective inner regions 57 via mounting hubs 101. In particular,
each hub 101 of adjacent discs 60 are coupled via a mounting pin
102 received within a corresponding bore 103 extending axially
through each hub 101. Accordingly, stack 54 comprises respective
pairs of discs 60 that are connected together in an alternating
sequence in the axial direction via their outer regions 56 and
inner regions 57. The axial endmost discs 60 are accordingly
attached to a mounting flange (not shown) corresponding to
respective upper and lower metal coupling flanges 76, 89 with the
discs 60 sandwiched axially between the upper and lower flanges (or
plates). With the stack 54 mounted in position at pulley 42 and
uppermost disc 60 of the stack is attached to outer race 69 and a
lowermost disc 60 of the stack is attached to inner race 67.
Accordingly, both the drive and the reaction torque are transmitted
through discs 60 and in particular spokes 58 that are configured to
deflect in the circumferential direction (by rotation) such that
outer collar 105 is capable moves radially inward and outward
relatively to inner race 67 (and axis C). As will be appreciated,
the number, shape and configuration of spokes 58 may be selected
accordingly to further embodiments to suit the elastic deformation
characteristic of the coupling 32.
[0059] According to further embodiments, coupling 32 being
positioned in the drive transmission between outer race 69 and
inner race 67 and may comprise a spring, and in particular a
torsion spring, a coil spring, a helical spring, a fluid (or
liquid) spring, a torsion disc spring or a compression spring.
[0060] Also, the deformable coupling 32 may be positioned at
different regions of pulley 42 and in particular intermediate in
the drive transmission pathway between outer race 69 and inner race
67 including for example between inner race 67 and bearing housing
72; inner race 67 and adaptor shaft 81; adaptor shaft 81 and outer
race 69 or a combination of these different positions. In
particular, the torsional responsive pulley 42 is described
according to a further embodiment in which deformable coupling 32
is positioned between inner race 67 and bearing housing 72. Being
similar to the embodiment of FIGS. 3 and 4, coupling 32 comprises a
modular assembly having first and second elastomeric rings 140, 143
secured between respective upper and lower mounting plates 141,
142. A metal disc spring 146 partitions the upper and lower
elastomeric rings 140, 143 and is configured to allow a degree of
independent rotational motion of rings 140, 143 resulting from
torque induced by the motion of unbalanced weight 30. Lower plate
142 is mounted at its radially inner region 144 to a radially
outward extending flange 145 projecting from bearing housing 72 as
described with reference to FIGS. 3 and 4. Similarly, a radially
inner region 144 of upper plate 141 is coupled to a radially
outward extending flange 150 projecting from an upper region of
inner race 67 that supports lower torsion rod 37 as described with
reference to FIGS. 3 and 4. Accordingly, drive and reaction torque
is transmitted between bearing housing 72 and inner race 67 via
flexible coupling 32. Accordingly, the undesirable reaction torque
is dissipated dynamically by the rotational twisting of elastomer
rings 140, 143 and the movement of the intermediate disc spring
146.
* * * * *