Patent Publication Number: US-11642678-B2

Title: Torque reaction pulley for an inertia cone crusher

Description:
RELATED APPLICATION DATA 
     This application is a continuation of U.S. patent application Ser. No. 16/062,699 filed Jun. 15, 2018, which is a § 371 National Stage Application of PCT International Application No. PCT/EP2015/080433 filed Dec. 18, 2015. 
    
    
     TECHNICAL FIELD 
     The present disclosure 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 
     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 driveably 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. Nos. 7,954,735; 8,800,904; EP 2535111; EP 2535112; US 2011/0155834. 
     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 apparatuses, which is a particular disadvantage where such crushers are positioned within extended material processing lines. 
     SUMMARY 
     An objective of the present solution is 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. 
     It is a further 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. 
     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 includes 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 suppress, dampen, dissipate or diffuse the reaction torque and inhibit or prevent direct transmission into at least regions of the drive transmission components. 
     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. 
     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. 
     According to a first aspect 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. 
     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. 
     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. 
     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. 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. 
     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. 
     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. The torque reaction coupling can be positioned on the central longitudinal axis of the crusher such that the axis of the pulley is coaxial with the crusher longitudinal axis. 
     The elastic component can be 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 be bolts, screws, pins, clips, cooperating threads, push-fit or snap-fit connections to allow releasable mounting of the elastic component at the pulley. 
     The elastic component can be mounted at one end of the pulley. For example, the elastic component is mounted at a lower end of the pulley when the pulley is secured in position at the crusher. 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, at least parts of the attachments are positioned externally at the pulley. 
     Optionally, the drive transmission within which the present torque reaction pulley is positioned includes 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 include 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. 
     Optionally, the torque reaction pulley includes 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. 
     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. 
     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 include 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. 
     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. The belt support includes 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. The grooves may include a V-shaped cross-sectional profile and extend 360° around the belt support. 
     The drive output portion has 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 may include 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. 
     Optionally, the pulley includes a first adaptor flange coupled between and connecting the input portion and the elastic component. Optionally, the pulley further includes a second adaptor flange coupled between and connecting the output portion and the elastic component. The first and second adaptor flanges are resiliently deformable. The adaptor flanges may be annular and include respective elastomeric rings. 
     The elastic component may include at least one elastomeric component configured to twist in response to the transmission of the torque through the pulley. With such a configuration 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. 
     Optionally, the elastic component includes 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. The elastic component includes 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. 
     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 include 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. 
     Optionally, the elastic component includes a spring. Optionally, the spring is a helical or coil spring. Optionally, the spring includes 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 includes 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. 
     Optionally, the elastic component includes 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. 
     Optionally, the torque reaction pulley includes 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. 
     Optionally, the spring includes a stiffness in range 100 Nm/degrees to 1500 Nm/degrees. Optionally, the spring includes a damping coefficient (in Nm·s/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 enables 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°. Accordingly, the elastic reaction coupling is configured to twist internally (with reference to its connection ends) by an angle up to 90° 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°, 10 to 40°, 10 to 30°, 10 to 25°, 15 to 20° or 20 to 30°. 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°) deflection. Optionally, the torsion responsive coupling includes a maximum deflection, that may be expressed as a twist of up to 70°, 80°, 90°, 100°, 110°, 120°, 130° or 140° 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. 
     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. 
     According to a second aspect there is provided an inertia cone crusher comprising a pulley as claimed herein. 
     According to a third aspect there is provided an inertia crusher having 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. 
     The present torque reaction pulley is 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. 
     The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a cross-sectional view through an inertia cone crusher according to present disclosure. 
         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. 
         FIG.  3    is a cross-sectional perspective view of a torque reaction pulley being a drive input component of the crusher of  FIG.  1   . 
         FIG.  4    is a further cross-sectional view of the pulley of  FIG.  3   . 
         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. 
         FIG.  6    is a further cross-sectional perspective view of a region of the elastically deformable component of  FIG.  5   . 
         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 
       FIG.  1    illustrates an inertia cone crusher  1  in accordance with one embodiment of the present disclosure. The inertia crusher  1  includes a crusher frame  2  in which the various parts of the crusher  1  are mounted. Frame  2  includes an upper frame portion  4  and a lower frame portion  6 . Upper frame portion  4  may have 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. 
     Lower frame portion  6  supports an inner crushing shell arrangement represented generally by reference  14 . Inner shell arrangement  14  includes 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. 
     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 . 
     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  includes 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 driveably 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  includes 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. 
     According to a specific implementation, drive mechanism  55  includes 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 centered 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. 
     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. 
       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 α, 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 α 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°, at a uniform speed, and at a static distance from the vertical reference axis C. 
     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 . 
     Torque reaction coupling  32 , includes 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 arranged 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 . 
     Referring to  FIGS.  3  and  4   , the drive pulley  42  includes 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  includes 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 includes 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 . 
     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  includes 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°) 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. 
     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 . 
     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 . 
     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 α and the non-circular orbiting motion of the unbalanced weight  30 . In particular, coupling  32  is configured specifically to absorb and dissipate torque. 
       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  includes a stack  54  of metal discs  60  that each includes 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 includes corresponding flanges  59 . 
     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  includes 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 . 
     According to further embodiments, coupling  32  being positioned in the drive transmission between outer race  69  and inner race  67  and may include 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. 
     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. 
     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 . Similar to the embodiment of  FIGS.  3  and  4   , coupling  32  includes 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 . 
     Although the present embodiments have been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiments be limited not by the specific disclosure herein, but only by the appended claims.