Roller, eccentric roller crusher, method of assembling or maintaining an eccentric roller crusher and lock system for an eccentric roller crusher
Patent Information
- Application Number
- AU2025375204
- Authority / Receiving Office
- AU · AU
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-05-13
- Filing Date
- 2025-05-08
- Publication Date
- 2026-08-27
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Field of the Invention A roller for an eccentric roller crusher is disclosed herein. An eccentric roller crusher including the roller is also disclosed. A method of assembling or maintaining an eccentric roller crusher is also disclosed. Background An eccentric roller crusher is a device for crushing material, usually rocks and minerals, and it comprises a rocker and a roller. The roller has a roller body that is a generally cylindrical piece that is mounted eccentrically on a central shaft of the roller. When the central shaft is driven to rotate, the roller body moves eccentrically relative to a central axis of the central shaft. The roller body is typically mounted such that it is free to rotate relative to the central shaft and may, for example, be mounted to the central shaft via bearings. The rocker (sometimes called a “swing arm” in the art) provides a curved surface that faces towards the curved outer surface of the roller. The curved surface of the rocker is one crushing surface of the eccentric roller crusher. Wear plates that form the outer surface of the roller provide another crushing surface of the eccentric roller crusher. Material is fed from generally above the roller into the region between the rocker and the roller. An upper part of the curved surface of the rocker is located relatively far from the roller and the curved surface approaches closer to the rocker towards its lower part, such that the space between rocker and roller starts off large at the upper end and gets gradually smaller towards the lower end. When the central shaft rotates, the roller moves in an eccentric manner, such that the radial distance between the surface of the roller and a given point on the rocker changes periodically. That is, the roller surface moves closer-to, then further-from, then closer-to (etc.) any given point on the surface of the rocker. This “back and forth” motion provides the crushing action of the eccentric roller crusher by alternatingly crushing and releasing the material such that the material can slide further down in the gap between rocker and roller, towards an exit gap of the crusher. Material falling out of the exit gap may be collected in a bucket or hopper or may be conveyed away by a conveyer belt. A plurality of wear plates are mounted on the outer circumferential surface of the roller body. These provide the crushing surface of the roller and they wear out over time and need to be replaced. To ensure the safety of both the eccentric roller crusher and any workers working on the crusher, it is necessary to prevent rotation of the roller while wear plates are being removed from the roller and when wear plates are being installed 1 onto the roller. Otherwise the roller may move unexpectedly, particularly when a wear plate is removed and the center of gravity of the roller suddenly changes. The present disclosure provides a solution to this. Summary of the Invention According to a first aspect, there is provided a roller for an eccentric roller crusher, the roller comprising: a central shaft; a roller body mounted for rotation relative to the central shaft; and braking means for preventing rotation of the roller body relative to the central shaft. As the roller is for use in an eccentric roller crusher, the roller body is mounted eccentrically on the central shaft. The braking means may allow maintenance to be carried out on the roller without the risk of unexpected or undesirable rotation of the roller. When the braking means are applied, relative rotation of the roller body and the central shaft is prevented. During this time, the central shaft (alone) may be braked or may be driven to rotate and, in either case, the roller body does not rotate relative to the central shaft. Thus, for example, wear plates mounted to the outer surface of the roller may be removed safely while the roller is braked relative to the central shaft. That is, the braking means locks the roller body relative to the central shaft. Without such a brake, removal of a wear plate could cause undesirable rotation of the roller relative to the shaft due to a sudden change in the center of gravity of the roller when a plate is removed. The central shaft may have its own braking mechanism or may be braked by a motor that is arranged to drive the central shaft (i.e. during crushing operations). It may be desirable to remove wear plates from a top of the roller (e.g. using a crane). In such circumstances, the braking means may be applied and a first, uppermost, wear plate may be removed from the roller body (and optionally, a new wear plate may be installed in its place). The central shaft may then be driven to rotate so as to bring a second wear plate to the uppermost position. The second wear plate may then be removed or replaced. The roller may comprise: a shaft locking hole that is located either on the central shaft or on a shaft fixed component that is fixed against rotation relative to the central shaft; a roller body locking hole that is located either in the roller body or on a roller fixed component that is fixed against rotation relative to the roller body; wherein the braking means comprises: a centering piece; wherein the centering piece is movable between a first position and a second position, wherein in the first position, the centering piece is simultaneously located at least partially within both the roller body locking hole and the shaft locking hole, to prevent relative rotation of the roller body and the central 2 shaft; and wherein in the second position, the centering piece is not located within at least one of the locking holes and thereby does not prevent relative rotation of the roller body and the central shaft. That is, the centering piece may sit within both locking holes and thereby prevent relative rotation of the two locking holes and thus prevent relative roation of the parts those holes locking holes are in. The same piece may perform both centering and locking. The centering piece may therefore be considered to be a locking piece or centering locking piece. The centering piece may have a circular cross-sectional shape along at least a portion of its length. The centering piece may have a non-circular cross-sectional shape along at least a portion of its length, such as a square, triangular, hexagonal, or oval crosssection, for example. The centering piece may be a centering bolt. The centering bolt may, for example, have threading or other engagement features along at least a portion of its length, such threading or engagement features intended to engage with complementary threading or features in a hold. The centering piece may be a centering pin. The centering pin may, in some examples, have no threading. The centering pin may be cylindrical. The centering pin may have a tapered end. The centering piece may have a substantially linear form. In other examples, the centering piece is not necessarily substantially linear, provided its shape allows it to be simultaneously located at least partially within both the roller body locking hole and the shaft locking hole. The roller body locking hole may be an axially-oriented roller body locking hole, and the shaft locking hole may be an axially-oriented shaft locking hole on the shaft fixed component. This may optionally allow the centering piece to be inserted from an axial end of the roller. This may, for example, be easily accessible as the axial end of the roller will not typically have significant buildup of any autogenous layer that needs to be cleaned off before the centering piece is inserted. The roller body locking hole may be a radially-oriented roller body locking hole; and wherein the shaft locking hole may be a radially-oriented shaft locking hole formed in the central shaft. This may optionally allow a user to easily rotate the roller by hand, via leverage from the centering piece within the roller locking hole, so as to more easily find the or a shaft locking hole. The shaft fixed component may comprise a centering iocking disc; wherein the shaft locking hole is a radially-oriented shaft locking hole formed in the centering locking 3 disc; and wherein the roller body locking hole is a radially-oriented roller body locking hole. The centering locking disc may optionally bring the shaft locking holes closer to a radially-inward side of the roller body locking hole, which may allow for a shorted centering piece to be used. This may be helpful in crushers with more-limited space between the rocker and the roller. The centering locking disc may comprise a plurality of radially-oriented shaft locking holes. This may optionally make it easier for a worker to find a shaft locking hole, after the centering piece has been inserted through the or a roller body locking hole. That is, in cases where there is only one shaft locking hole, the worker may need to rotate the roller by hand through a large angle before finding the position in which the roller body locking hole and the shaft locking hole are aligned. The centering locking disc may be located between two bearings which support the roller body for rotation relative to the central shaft. The centering locking disc may be located axially outward of two bearings which support the roller body for rotation relative to the central shaft. Each locking hole may include an outwardly expanding tapered portion at its radially outer side. For example, each shaft locking hole may include an outwardly expanding tapered portion at its radially outer side. This may optionally help to guide an end of the centering piece into the locking hole / shaft locking hole. The tapered portion of each shaft locking hole may contact the tapered portions of two adjacent shaft locking holes. This may optionally assist insertion of the centering piece by ensuring that, regardless of the relative orientation of the roller and the shaft, the centering piece will either immediately enter a shaft locking hole or will come into contact with a tapered portion of a shaft locking hole which then helps guide the centering piece into its respective shaft locking hole. In the second position, the centering piece may be removed from the roller body locking hole. That is, the centering piece may be removed from the entire roller when it is not required, and may be stored separately. In other examples, the centering piece may be part of the roller such that it is not easily removed. For example, the centering piece may, in the first position, be located internally of the roller and may be controlled to move between the first and second positions by automatic means (magnetic, hydraulic, electrical, electromagnetic etc.) The roller body locking hole may be accessible from an outer side of the roller. The roller may optionally further comprise a removable bolt or removable cover arranged to prevent debris from passing through the roller body locking hole. The removable bolt 4 or cover may optionally prevent dust or debris from entering into the roller during crushing operations. The removable bolt or cover may then be removed during maintenance or construction operations to allow the centering piece to be inserted into the roller body locking hole. The centering piece may have a first end and a second end, wherein a portion of the centering piece including the first end has a tapered shape or a pointed end. The tapered or pointed end may optionally help guide the centering piece into a respective locking hole during insertion of the bolt. A portion of the centering piece that includes the second end may be configured to receive a tool for applying torque to the centering piece. This may optionally make it easier for a worker to install the centering piece in cases where the centering piece includes threading to connect to the locking hole and / or a roller body locking hole. An outer diameter of the screw threading may be a largest diameter of the centering piece along its length. The roller may further comprise one or more wear plates mounted to an outer surface of the roller body. The wear plates may optionally provide a hard surface for crushing operations and may be replaced after an amount of wear has occurred, without requiring replacement of the roller. One or more of the one or more wear plates may include a wear plate hole therethrough or a wear plate cutout section, wherein the wear plate hole or cutout section allows access to the roller body locking hole from the radially outer side of the roller. This may optionally allow easy access to the roller body locking hole without requiring any initial adjustment or movement of any of the wear plates. The braking means may comprise a brake pad, wherein the brake pad is either a) fixed against rotation relative to the roller body and configured to releasably load against either the central shaft or against a shaft fixed component that is fixed against rotation relative to the central shaft: or b) fixed against rotation relative to the shaft and configured to releasably load against either the roller body or against a roller body fixed component that is fixed against rotation relative to the roller body. This may optionally allow braking of the roller without requiring a centering piece. The brake pad may be manually actuated or actuated by automatic means (e.g. magnetic, hydraulic, electrical, electromagnetic etc.). The brake pad may be mounted on a brake calliper. The brake pad may be mounted adjacent to a brake disc. The roller may comprise a second brake pad, wherein the second brake pad is either the shaft fixed component or the roller body fixed component. The roller may further comprise automated locking means configured to activate the braking means to prevent relative rotation of the roller body relative to the central shaft. The automated locking means may comprise an electrical system and / or a hydraulic system. The automated locking means may be configured to move the centering piece from the second position to the first position. In other embodiments, the automated locking means may move the brake pad (or both the brake pad and second brake pad) to prevent relative rotation of the roller and the central shaft. According to a second aspect, there is provided an eccentric roller crusher comprising: a rocker: and the roller according to any preceding claim. According to a third aspect, there is provided a method of assembling or maintaining an eccentric roller crusher, wherein the eccentric roller crusher comprises the roller according to any of the aspects disclosed herein, the method comprising: 1) activating the braking means to prevent relative rotation of the roller body relative to the central shaft; 2) optionally, removing one or more wear plates that are mounted on the roller body; 3) installing one or more wear plates on the roller body; and 4) deactivating the braking means to allow relative rotation of the roller body relative to the central shaft. This may optionally allow safe removal and installation of wear plates on a roller without the risk of unexpected rotation of the roller during the operation. According to a fourth aspect, there is provided a lock system for an eccentric roller crusher that comprises a central shaft and a roller body that is mounted for rotation relative to the central shaft, the lock system comprising: a centering locking disc; and a centering piece; wherein the centering locking disc is mountable to the central shaft and fixable against rotation relative to the central shaft; wherein a plurality of radially-oriented shaft locking holes are formed around a circumference of the centering locking 6 disc, each shaft locking hole having a respective locking hole depth in the radial direction of the centering locking disc; and wherein the centering piece is configured to fit into any one of the locking holes, the centering piece having a length defined between a first end and a second end of the centering piece. The centering piece length may be greater than the locking hole depth such that the centering piece extends radially outward from the centering locking disc when it is inserted into a hole. In this manner, the centering piece may bear against some portion of the roller body to prevent rotation between the roller body and central locking disc. In other embodiments, the centering piece may be shorter than the locking hole depth, such that the centering piece only partially sits in the locking hole when it locks the roller body against rotation relative to the central shaft. The central locking disc may describe an annulus having a minimum radius and a maximum radius. The locking hole depth may be equal to the difference between the minimum radius and maximum radius. When installed on a central shaft, the outer surface of the central shaft may define a base of the hole. In this case, the locking hole depth is equal to the radial distance between the central shaft outer surface and the maximum radius. The lock system may be part of the initial design of an eccentric roller crusher (hereafter “crusher”). Alternatively, the roller of an existing crusher may be retrofitted with the lock system. Some existing designs of crusher have unused empty space inside the roller body that is suitable for receiving the centering locking disc. In such designs, a roller body locking hole may need to be drilled into the roller body to allow the centering piece to be inserted. When the lock system is installed in a crusher, the centering piece may be inserted into one of the shaft locking holes and may bear against some part of the roller body (e.g. a roller body locking hole) to prevent rotation of the roller relative to the central shaft. The portion of the centering piece configured to receive a tool for applying torque may have a cross-sectional shape in a plane transverse to an axis joining the first end and the second end, wherein the cross sectional shape includes at least two flat surfaces. For example, this portion may be polygonal (e.g. octagonal, hexagonal etc.), which shape allows a wrench to be used to rotate the centering piece. Alternatively, the portion may have two or more flat surfaces defining a drive of the centering piece. The drive may, by way of non-limiting example, be shaped to receive a flat-head screwdriver or a Phillips head screwdriver, or a hex key. The centering piece may include screw threading along at least a portion of its length. This may allow the centering piece to be screwed into a given locking hole. This may prevent the centering piece from falling out after installation. An outer diameter of the screw threading may define the largest diameter of the centering piece along its length. This may allow the entire centering piece to fit through a given hole having threading corresponding to the centering piece screw threading. That is, the centering piece may be screwed through the threading to a point where the engagement part is flush with, or below the level of, a radially outer side of a roller body locking hole. This placement may ensure the centering piece does not interfere with moving the wear plates onto or off from the roller body. Each locking hole may include screw threading configured to engage with the screw threading of the centering piece. That is, the roller body locking hole may have roller body locking hole screw threading, wherein the roller body locking hole screw threading is configured to engage with the screw threading of the centering piece. Alternatively or additionally, the shaft locking hole may have shaft locking hole screw threading, wherein the shaft locking hole screw threading is configured engage with the screw threading of the centering piece. This may optionally allow the centering piece to pass entirely through a given locking hole. This may allow the centering piece to be semi-permanently fixed in position through engagement of the screw threading of the centering piece with the screw threading of a locking hole in which the centering piece sits. This may prevent the centering piece from undesirably falling out, wherein the centering piece falling out would suddenly allow rotation of the roller relative to the central shaft. Each locking hole may include an outwardly expanding tapered portion at its radially outer side. That is, the tapered portion may provide a generally frustoconica! surface, that expands outwardly along a radial direction from a center of the central locking disc. The tapered portion of a given locking hole may optionally help to guide the centering piece towards that hole when a worker is inserting the centering piece. The tapered portion of each shaft locking hole may contact the tapered portions of two adjacent shaft locking holes. This may ensure that, regardless of the current relative orientation of the roller body and central shaft, when the centering piece is inserted towards the shaft, it will either enter directly into a shaft locking hole or (more likely) will contact one of the tapered portions and be guided by that tapered portion into its respective shaft locking hole. Alternatively or additionally, a minimum angular distance, measured around the circumference of the central shaft, between the tapered portion of one shaft locking hole and the tapered portion of an adjacent shaft locking hole may be less than 5 degrees, and preferably less than 2 degrees. This may minimise the maximum angle that a roller body needs to be rotated through before the centering piece can enter a shaft locking hole. The length of centering piece may be set such that, when one end of the centering piece is as least partially in one of the shaft locking holes, the other end of the centering piece is at least partially in the roller body locking hole. In this manner, the centering piece may sit in both locking holes simultaneously and thereby prevent relative rotation of the roller body relative to the central shaft. One or more of the one or more wear plates may include a wear plate hole therethrough or a wear plate cutout section, wherein the wear plate hole or cutout section allows access to the roller body locking hole from the radially outer side of the roller. In this manner, the wear plate(s) do not inhibit access to the roller body locking hole. Alternatively or additionally, the wear plates may be arranged such that there is a gap between two adjacent wear plates and the roller body locking hole is accessible via the gap. The roller body locking hole may have roller body locking hole screw' threading, wherein the roller body locking hole screw threading is configured to engage with the screw threading of the centering piece. This may allow the centering piece to screw into the roller body, which may therefore prevent the centering rod from falling out of the locking hole(s). According to a fifth aspect, there is provided a method of locking an eccentric roller crusher, wherein the eccentric roller crusher comprises: a roller comprising: a central shaft; a roller body mounted for rotation relative to the central shaft; the roller body including at lease one radially-oriented roller body locking hole that is accessible from a radially outer side of the roller; one or more wear plates mounted on a radially outer surface of the roller body; and a centering locking disc mounted on the central shaft and fixed to rotate with the central shaft; and wherein a plurality of radially-oriented shaft locking holes are formed around a circumference of the centering locking disc, each shaft locking hole having a respective locking hole depth in the radial direction of the centering locking disc; and the roller body including at lease one radially-oriented roller body locking hole that is accessible from a radially outer side of the roller; the method comprising: inserting a centering rod through the roller body locking hole and 9 into one of the shaft locking holes such that the centering rod prevents rotation of the roller body relative to the central shaft. The method of locking an eccentric roller crusher may be performed on the eccentric roller crusher according to the fourth aspect. The above-disclosed methods may improve the safety of a maintenance procedure on an eccentric roller crusher or the safety of the initial construction of an eccentric roller crusher. During maintenance, one or more of the one or more wear plates may need to be removed from the crusher. When a wear plate is removed, the center of gravity of the roller may change and the roller body may unexpectedly rotate if it is not locked against rotation. This could cause injury to a worker and / or damage to the crusher. Thus, locking the roller body against rotation before any wear plates are removed improves the safety of the crusher during maintenance. Similarly, when a crusher is first being constructed, wear plates need to be mounted to the roller and this may occur once the roller is already mounted on the central shaft. When any given wear plate is added onto the roller, the center of gravity of the roller may change and the roller body may unexpectedly rotate if it is not locked against rotation. This could cause injury to a worker and / or damage to the crusher. Thus, locking the roller body against rotation before any wear plates are installed, and keeping the roller body locked against rotation until all wear plates have been installed, also improves the safety of the crusher during initial construction. Braking means may then be released (e.g. the brake released or the centering piece removed, as appropriate) before the crusher commences crushing operations. After the step installing one or more wear plates on the roller body: the methods may include removing the centering rod from the locking hole and roller body locking hole, to allow relative rotation of the roller body and the central shaft; and may optionally include: blocking the roller body locking hole to prevent material from passing through the roller body locking hole. Blocking the roller body locking hole may be achieved by inserting a bolt or plug into the roller body locking hole or applying a cover over the roller body locking hole. According to a sixth aspect, there is provided a method of retrofitting an eccentric roller crusher, wherein the eccentric roller crusher comprises: a roller comprising: a central shaft; a roller body mounted for rotation relative to the central shaft; one or more wear plates mounted on a radially outer surface of the roller body; the method comprising: providing the lock system according to the fourth aspect; mounting the centering 10 locking disc on the central shaft and fixing for rotation with the central shaft; and, if required, forming at least one rolier body looking hole in the roller body such that the at least one roller body locking hole is aligned with the shaft locking holes along an axial length of the central shaft, wherein the roller body locking hole is accessible from a radially outer side of the roller when the wear plates are mounted on the roller body, wherein the roller body locking hole is configured to receive the centering piece therethrough. In this case, “aligned” means that the axes of the roller body locking hole and shaft locking hole are sufficiently close to being coaxial that, within the tolerances of the various parts, the (straight) centering rod is able to extend from the roller body locking hole into the locking hole. That is, exact mathematical alignment of the two axes is not essential, merely a sufficient level of alignment for the rod to simultaneously sit within both holes. This method may provide improved safety of the eccentric roller crusher, by allowing relative rotation of the roller body and central shaft to be blocked using the lock system, e.g. during maintenance operations on the crusher. Brief Description of the Drawings Reference will now be made, by way of example only, to the accompanying drawings in which: Figures 1 and 2 each show a cross-sectional view through the eccentric roller crusher; Figure 3 shows a cross sectional view through a roller of the eccentric roller crusher; Figure 4 shows a perspective view of the roller; Figure 5 shows a zoomed-in view on a portion of Figure 3; Figure 6 shows a centering bolt; Figures 7A-C show various views of a centering locking disc; Figures 8A-C show various view of another centering locking disc; Figure 9 shows an exploded perspective view of the roller with the centering bold installed; Figure 10 shows a cutaway perspective view of a roller body; Figure 11 shows a cross sectional view through another design of roller that lacks the centering locking disc; Figure 12 shows a cross sectional view through another design of roller having axially-oriented locking holes; Figure 13 shows a cross sectional view through another design of roller having automated locking means: and Figure 14 shows a cross sectional view through another design of roller having a brake unit. Detailed Description Figure 1 shows cross-sectional side view of an eccentric roller crusher 100 (hereafter “crusher 100”) and Figure 2 shows the same cross-sectional side view of the crusher 100 of Figure 1 but with different parts and regions labelled. The crusher 100 has a housing 102. The crusher 100 comprises a rocker 110 and a roller 120. The rocker 110 provides a rocker wear surface 112 mounted on a mounting body 114. The mounting body 114 is mounted to the housing 102. The roller 120 comprises a central shaft 122 having a central axis X. The rocker wear surface 112 describes a generally curved profile that is substantially concave when viewed from the axis X. The radial distance between the axis X of the central shaft 122 and the rocker wear surface 112 is greatest at a vertically upper end of the rocker wear surface 112. This radial distance between the axis X and the rocker wear surface 112 gradually decreases and is smallest at a vertically lower end of the rocker wear surface 112. An exit gap E (see Figure 2) is formed between the roller 120 and the rocker 110 at the vertically lower end of the rocker 114. A drive mechanism 118 is provided to drive the central shaft 122 for rotation. The drive mechanism 118 may, for example, connect via a belt to a counterweight disc 136b (see Figure 3), to drive the counterweight disc 136 and thereby drive the central shaft 122 for rotation. In use, the central shaft 122 is driven to rotate about the axis X. A roller body 126 is mounted with respect to the central shaft 122. A plurality of wear plates 128 are mounted to the roller body 126. A material infeed 129 is used to deliver material to be crushed to an upper side of the roller 120. In Figure 1, a centering locking disc 200 is mounted on the central shaft 122 and is connected to the central shaft 122 such that centering locking disc 200 is fixed to rotate with the central shaft 122. In some embodiments, there are twelve (12) wear plates 128. However, more or fewer wear plates 128 may be provided, as required. The roller body 126 is rotatable relative to the central shaft 122. in the orientation shown in Figures 1 and 2, where 12 o’dock defines the verticaiiy-upward direction, the vertically upper end of the rocker wear surface 112 is at approximately the 1 o’clock position and the vertically lower end of the rocker wear surface 112 is at approximately the 5 o’clock position. The gap between the vertically upper end of the rocker wear surface 112 and the outer surface of the roller 120 maybe called an inflow gap G, said inflow gap being generally indicated by a dashed line in Figure 2. The gap between the vertically lower end of the rocker wear surface 112 and the outer surface of the roller 120 forms an exit gap E of the crusher, said exit gap being generally indicated by a dashed line in Figure 2. In the orientation shown in Figure 2, the central shaft is, in use, driven to rotate in the clockwise direction. A crushing space C is defined between the inflow gap G, the exit gap E, the rocker wear surface 112 and the outer surface of the roller 120, as shown in Figure 2. The roller body 126 is mounted eccentrically on the central shaft 122, as shown in Figure 3. A circular cam portion 122a of the central shaft 122 is formed such that a radial center of the cam portion 122a is offset from the axis X. That is, the circular portion 122a has a center axis Y that is parallel to, and separated from, the axis X by a distance d. The roller body 126 is connected to this cam portion 122a. Consequently, as the central shaft 122 rotates about its axis X, the roller body 126 and wear plates 128 move in an eccentric motion around the axis X. This eccentric mounting is also depicted in Figures 1 and 2 as a dashed circular line. The dashed circular line shows the cam portion 122a and how it is offset by a distance d from the central axis X of the central shaft 122. A first pair of bearings 132a,b are provided in which a radially inner part of each bearing 132a,b is mounted on the cam portion 122a and a radially outer part of each bearing is mounted to the roller body 126. As such, the roller body 126 can rotate relative to the shaft 122 around axis Y. A second pair of bearings 130a,b are provided. A radially inner part of each of the second pair of bearings 130a,b Is mounted to the central shaft 122 and not on the cam portion 122a, and a radially outer part of each of the second pair of bearings 130a,b is mounted on, or mounted relative to, the housing 102 of the crusher 100. The second pair of bearings 130a,b support the central shaft 122 for rotation around the axis X. A counterweight disc 136a,b is provided at either end of the central shaft 122. Each counterweight disc has weights 137a,b attached on one side. The weights 137a,b are respectively located on each counterweight disc 136a,b so as to balance out the eccentrically mounted roller body 126 and thereby reduce loading on the second pair 13 of bearings 130a,b. One of the counterweight discs 136b may also receive a drive belt (not shown) on its outer circumference, where the drive belt connects the central shaft 122 to the drive mechanism 118. The central locking disc 200 is mounted on the cam portion 122a. In Figure 3, the central locking disc 200 is mounted between the first pair of bearings 132a,b. However, other mounting locations are possible. For example, the central locking disc may be mounted axially outward from one or other of the first pair of bearings 132a,b. The central locking disc 200 has a plurality of radially-oriented locking holes 202. The roller body 126 has at least one roller body locking hole 125 therein. In the example shown in Figure 2, there are twelve (12) roller body locking holes 125, where each roller body locking hole is located beneath a respective one of the wear plates 128. However, more or fewer roller body locking holes may be used. The roller body locking hole(s) 125 and central locking disc 200 are described in further detail hereinbelow. In use, the material infeed 129 is used to deliver material for crushing (labelled with the “Input" arrow' in Figures 1 and 2) to the vertically upper side of the roller 120, i.e. at or near the 12 o’clock position. Under the influence of gravity and / or due to further material coming in therebehind, the material to be crushed passes the inflow gap G and moves into the crushing space C. The material infeed 129 may be a grating that has a plurality of slits and / or holes therein. These slits or holes allow' small material to fall through the infeed 129 and thereby avoid entering the space C. The size of the slits / holes may be selected to allow material to fall through that has a size equal to, or smaller than, a smallest size of the exit gap E. This may avoid unnecessary energy expenditure in crushing material that is already sufficiently small, i.e. that is already comparable in size to the size of material exiting from the exit gap E. This material that does not need to be crushed may be collected in a hopper, bin, or on a conveyer belt, as desired. Material that is larger than the slits or holes passes into the crushing space C. Thus, the crusher 100 may have two output streams, as indicated by the “Output” arrows on Figures 1 and 2. These output streams may optionally be collected in the same hopper / bin / conveyer belt, as desired. One output stream is material that has passed through the crushing space C and the other output stream is material that has fallen through the material infeed 129 without entering the crushing space C. Due to the eccentric motion of the roller 120, the distance between any given point on the rocker wear surface 112 and the nearest part of the wear plates 128 to that given 14 point is changing periodically. That is, from the perspective of any given point on the rocker wear surface 112, the roller surface is periodically moving to-and-fro (i.e. is moving towards and then away from the given point). In general, a given piece of material (e.g. “a rock”) enters the crushing space C and will continue through the crushing space C until it reaches a point where it bears against a point on the rocker wear surface 112 and a point on the wear plates 128 of the roller. If the roller 120 is at a point of its eccentric motion where the wear plates 128 are moving towards that point on the rocker wear surface 112, then the rock will be crushed, i.e. by the dosing of the gap between wear pads 128 and rocker 110. If the roller 120 is at a point within its eccentric motion where it is moving away from the aforesaid point on the rocker wear surface 112, then the rock will continue further into the crushing space C (i.e. under the action of gravity and / or more material pushing it from behind), towards the exit gap E, until it reaches a narrower portion of the space C where it again bears against both the roller 120 and rocker 110. Provided the rock is sufficiently large, it will eventually find its way to a part of the crushing space C where it can no longer move towards the exit gap E and it will remain there until the eccentric motion brings the wear plates 128 towards said rock, at which point the rock will be crushed between the roller 120 and rocker 110. An initially-large rock may undergo multiple crushing actions within space C before its component parts exit in pieces from the exit gap E. Material exiting the exit gap E must have at least one dimension smaller than the radial size of the exit gap E. The exit gap E size varies periodically due to the eccentric motion of the roller 120. As may be seen from the discussion hereinabove, the crushing space C is larger at the inflow gap G side and smaller towards the exit gap E side. This means that any given rock being crushed in the crusher 100 is being “squeezed from below” due to the eccentric motion of the roller 120. Consequently, the reaction force on the wear plates 128 from the rock tends to bias the roller body 126 and wear plates 128 in the opposite direction to the rotation direction of the central shaft 122. That is, in the orientation shown in Figure 2, the central shaft 122 is rotating clockwise during operation and the roller body 126 and wear plates 128 are gradually turned counter-clockwise due to the reaction forces from the material being crushed. This means that, over time, different parts of the outer surface of the roller 120 (i.e. different portions of the wear plates 128) are brought to face towards the rocker wear surface 112. This feature helps to even out wear on the wear plates 128, compared to a roller 120 that cannot rotate relative to its central shaft 122. Figure 4 shows a perspective view of the roller 120. The wear plates 128 are attached to the roller body 126 by bolts 127 at either end of each wear plate 128. Each wear plate 128 additionally has a wear plate hole 128a that is aligned with a respective roller body locking hole 125. As such, each roller plate hole 125 can be accessed from a radially outer side of the roller 120, via the wear plate holes 128a, while the wear plates 128 are mounted on the roller body 126. In another example, not shown, there may be a gap between two adjacent wear plates and the roller plate hole 125 may be formed in the gap. In a further example, not shown, one or both of two adjacent wear plates 128 may have a cutout section in an edge of the wear plate, such that the roller plate hole 125 may be accessed via the cutout section. In each of these examples, the roller body locking hole(s) 125 may be accessed from outside the roller 120 while wear plates 128 are mounted on the roller body 126. Figure 5 depicts a zoomed-in view of Figure 3, focussed on the centering locking disc 200 and the roller body locking hole 125. The centering locking disc 200 has a generally annular shape. That is, the centering locking disc 200 has an inner radius and this is sized to fit over the cam portion 122a of a central shaft 122. The centering locking disc 200 has an outer radius. The centering locking disc 200 has a plurality of radially-oriented locking holes 202. That is, each locking hole 202 has a locking hole axis CLD that is oriented along a radially-extending line from a center of the disc 200. The or each roller body locking hole 125 is radially oriented as well. That is, the or each roller body locking hole has a central axis RB that is oriented along a radially-extending line from a center of the disc 200. The roller body locking hole axis RB intersects the cam portion axis Y at a given point along the cam portion axis Y, and the locking hole axis CLD intestects the cam portion axis Y at the same point along the cam portion axis Y. Put another way, the or each roller body locking hole 125 is at the same axial location (e.g. with respect to an end of the central shaft 122) as the locking holes 202 of the central locking disc 200. During operation of the crusher 100, a bolt 134 is installed in the roller body locking hole 125 to prevent material ingress into the roller, inside the wear plates 128. Alternatively, a cap over the roller body locking hole 125 may be provided for the same purpose. The bolt 134 may, in some designs, assist in mounting the wear plate 128 to the roller body 126. However, in other designs, the bolt 134 may act solely to fill the roller body locking hole 125, and not provide any mounting function for the wear plate 128. Each locking hole 202 of the centering locking disc 200 has a respective locking hole depth. In some examples, the locking holes 202 extend all the way through the 16 thickness of the annular central locking disc 200. In such cases, the depth of each locking hole may be equal to the outer radius minus the inner radius. Put another way, when such a centering locking disc 200 is installed on a central shaft 122, the central shaft 122 may provide the bottom to each locking hole 202. Alternatively, the depth may be less than this. That is, in some examples, each locking hole 202 does not extend all the way through the thickness of the annular central locking disc 200. A centering bolt 300 may be used to lock the roller body 126 against rotation relative to the shaft 122. The centering bolt 300 is one example of a centering piece (and therefore also of a “centering locking piece” or “locking piece”). In another example, a centering pin may be provided instead. A centering pin, for example, may have a smooth outer surface. A centering bolt may typically have at least some threading or other engagement features for interlocking with complementary features / threading in a hole. An example centering bolt 300 is shown in Figure 6. The centering bolt 300 is inserted through the roller body locking hole 125 and into one of the locking holes 202 of the centering locking disc 200, such that one part of the centering bolt 300 sits in the locking hole 202 at the same time as another part of the centering bolt 300 sits in the roller body locking hole 125. In this manner, the centering rod 300 prevents rotation of the roller body 126 relative to the central shaft 122 while it is installed. The locking holes 202 of the centering locking disc may therefore be termed “shaft locking holes” because they are formed in a component (i.e. the centering locking disc 200) that is fixed relative to the central shaft 122. Figure 6 shows the centering rod 300. A first end 302 of the centering rod 300 is pointed. Moving axially along from the pointed end 302, the centering rod 300 has a rod section 304 followed by a threaded section 306, and finally an engagement part 308 at the second end of the centering rod 300. The engagement part 308 shown in Figure 6 has an octagonal cross section, suitable to be gripped by a wrench. However other types of engagement part are envisaged, including, but not limited to, a screw drive, such as a drive configured to receive a flat head screwdriver, a drive for receiving a Phillips head screwdriver, or a drive for receiving a hex key. The engagement part 308 may be any design that allows a user to apply torque to the centering rod 300. In some examples, not shown, the rod section 304 does not exist and the threaded section 306 extends the entire way from the pointed end 302 to the engagement part 308. In other examples, not shown, the threaded section 306 is immediately adjacent the pointed end 302 and the rod section 304 is between the threaded section 306 and the engagement part 308. The centering bolt 300 may be sized such that the major diameter of the threaded section 306 (i.e. the radially outermost diameter of the threading) is the largest diameter of the centering rod 300. In this manner, for example, the engagement part 308 may sit entirely within the roller body locking hole 125 when the centering rod 300 is installed. The threading may, in some examples, not shown, extend along the entire length of the centering bolt 300. In other examples, not shown, the threading may extend the entire length between the pointed first end 302 and the engagement part 308. In other examples, the centering bolt 300 may have no threading at all, and possible examples of such centering bolts are described below. The roller body locking hole(s) 125 may be threaded with a thread that corresponds to the threaded section 306 of the centering rod 300. Alternatively or additionally, each of the locking holes 202 may be threaded with a thread that corresponds to the threaded section 306 of the centering rod 300. In this manner, the centering bolt 300 can be screwed into one or both of the locking holes 202 and / or roller body locking hole(s) 125. This may prevent the centering bolt 300 from unintentionally coming out from either of the holes 125 / 202 in which it sits while it locks the roller body 126 against rotation relative to the central shaft 122. In a different example, not shown, magnets may be used to releasably hold the centering rod in the locking holes. That is, for example, each locking hole 202 may contain a magnet in a base thereof and the centering bolt (or just one end thereof) may be magnetic or made of magnetisable material, such that when the centering rod enters a given locking hole, the magnet in the locking hole attracts the first end of the centering bolt. Alternatively, an end of the centering rod may be magnetic and the locking holes 202 or central shaft 122 may have a magnetisable material, such that the centering rod 300 is held within a given locking hole 202 by magnetic force. In such examples, the engagement part 308 may preferably not have a shape for receiving a torqueapplying tool (screwdriver etc.) but may instead have a shape that allows the centering rod to be pulled directly out from the roller body locking hole, such as a handle, a ring, or a hook-shaped piece. The centering bolt 300 is not present during normal crushing operation of the crusher 100. Thus, during normal operation of the crusher 100, the roller body 126 and wear plates 128 are free to rotate relative to the central shaft 122. The centering bolt 300 is installed whenever relative rotation of the central shaft 122 and the roller body 18 126 needs to be prevented. This may be during a procedure to replace one or more of the wear plates 128 or when first installing the wear plates 128, for example. An operation to replace one or more worn wear plates 128 may involve the following steps: 1) Operation of the crusher 100 is stopped and any material (rock etc.) is removed. 2) The central shaft 122 is locked against rotation about its own axis X, such as by applying a brake or by turning off the drive mechanism 118. 3) Optionally one or more of the wear plates 128 are hosed down / cleaned. 4) The bolt 134 or cap over the roller body locking hole 125 is removed. 5) The centering bolt 300 is inserted, pointed end 302 first, past one of the wear plates 128 (e.g. through hole 128a or in between two wear plates 128), and through the roller body locking hole 125, towards the central locking disc 200. 6) The pointed end engages with one of the locking holes 202 - this may require a few degrees of relative movement of the roller body 126 relative to the shaft 122, in order to bring the axes (CDL and RB) of the two holes 202 / 125 into alignment, so that the centering rod 300 can fully enter the locking hole 200. 7) The centering rod 300 is rotated when its threaded section 306 first engages with threading on one of the holes 202 / 125, so as to screw the centering rod 300 into said threading. 8) The bolts 127 mounting the one or more worn wear plates 128 to the roller body 126 are removed. 9) The one or more worn wear plates 128 are lifted off from the roller body 126. 10)New or refurbished wear plates 128 are mounted on the roller body 126 and bolted thereto using bolts 127. 11) The centering bolt 300 is removed by unscrewing the centering bolt 300 and removing it from the two holes 202 / 125. 12)The bolt 134 or cap over the roller body locking hole 125 is reinserted. 13)Operation of the crusher 100 is restarted. An operation to initially mount wear plates 128 to the roller body 126 is substantially similar, and primarily Includes steps 3-6 and 9-11, above. Figure 7A shows a perspective view of one design for the central locking disc 200. Figure 7B shows a zoomed-in section of the central locking disc 200 of Fig 7A. Figure 7C shows a cross-sectional view of the central locking disk of Figures 7A and 7B. The central locking disc has a plurality of radially-oriented holes 202 in its radially outer surface. Each hole 202 has a radially-outwardly extending frustoconical portion 202a and a cylindrical portion 202b radially inward from the frustoconical 19 portion 202a. The frustoconical portion 202a thus provides a tapered portion for each hole 202 Put another way, each hole 200 is generally funnel-shaped. This tapered portion may assist in bringing the roller body locking hole 125 and locking hole 202 into alignment when the centering rod 300 is inserted through these two holes. That is, the centering rod 300 may be inserted through the roller body locking hole 125 and advance towards the locking holes 202. The plurality of locking holes 202 extend all the way around the outer circumference of the central locking disc. That is, the locking holes 202 are disposed at equal angles around the circumference of the disc and the angle between the axis CLD of any two adjacent holes is small. For example, the central locking disc 200 may have fifty (50) locking holes and the radially-oriented axes CDL of any two adjacent locking holes 202 may be 360 / 50 = 7.2 degrees apart. Of course other numbers of locking holes 202 are envisaged. If one of the locking holes is nearly, but not fully, aligned with the roller body locking hole 125, then the pointed end 302 of the centering rod 300 may bear against the tapered portion and thus guide the centering rod 300 into the cylindrical portion 202b of that locking hole 202. In doing so, the roller body 126 may rotate slightly relative to the central shaft 122, until the roller body locking hole 125 is aligned with the respective one of the locking holes 202. That is, the tapered portion 202a may guide the centering rod 300 into a given locking hole 202. It is preferable however that the number of locking holes 202 is sufficiently large such that, at maximum, only a few degrees of relative rotation of the roller body 126 and central shaft 122 is required to bring the roller body locking hole 125 into alignment with one of the locking holes 202. This may make it easier for a worker to locate a locking hole 202 when inserting the centering bolt 300. In the example shown in Figure 7A-C, the tapered portion 202a of each locking hole 202 is generally circular and the circles described by the tapered portions 202a of each pair of adjacent locking holes 202 overlap. Put another way, the tapered portions 202a merge into one another. In this manner, it can be ensured that, regardless of the relative rotational positions of the roller body 126 and the central shaft 122, the pointed end 302 of the centering bolt 300 will always either: A) Enter straight into one of the cylindrical portions 202b, or B) Come into contact with one of the tapered portions 202a, such that further radially-inward movement of the centering bolt biases the roller body 126 and central shaft 122 to move to a relative orientation in which the pointed end 302 of the centering bolt 300 enters the cylindrical portion 202b. In other designs, the tapered portions 202a may be non-overlapping. The centra! locking disc 200 shown in Figure 7A and 7B has a flange 204. The disc 200 and flange 204 have a cutout section 206 that may, in some examples, engage with a spline on the central shaft 122 to fix the central locking disc 200 for rotation with the central shaft 122. The flange 204 has one or more bolt holes 208 that may allow the central locking disc 200 to be bolted to the central shaft 122. At a radially inner side of the central locking disc 200 there is a channel 210 and each of the locking holes 202 opens into the channel 210. The channel 210 may provide an outlet for any grease or dust that gets into a given locking hole 202. The centering rod 300 may push any such grease or dust into the channel 210. In some examples, the cutout section 206 may alternatively provide an outlet for grease that has accumulated in the channel 210. Figures 8A-C show an alternative design of central locking disc 400. This central locking disc 400 is substantially similar to the previously-described central locking disc 200 and like reference numerals are used for like features. Compared to the previously-described central locking disc 200, the central locking disc 400 of Figures 8A-C lacks the flange 204 and its associated features (e.g. bolt holes 208). Instead, the central locking disc 400 of Figures 8A-C connects to the central shaft 122 via a press fit. The central locking disc 400 has two cutout sections 406a,b. Similar to the previously-describe cutout section 206, the cutout sections 406a,b may engage with a spline on the central shaft 122 and / or may provide an outlet for grease or dust that gets into the locking holes 202. Figure 9 shows a cutaway perspective view of the roller 120 with the centering bolt 300 installed. Several components of the roller 120 are not visible in this view for clarity. Figure 9 specifically shows the central shaft 122 and its cam portion 122a. The centra! locking disc 200 is mounted on the cam portion 122a and the centering rod 300 extends into one of the locking holes 202 of the centering locking disc 200. The example shown in Figure 9 has a plurality of thread blocks 131 that connect (e.g. via bolts) to an inner side of the roller body 126 (note, the roller body 126 is not shown in Figure 9). Each thread block 131 has a threaded hole 131a therein and is mounted to the roller body 126 via bolts such that the threaded hole 131a is aligned with the roller body locking hole 125. When the thread blocks 131 are fixed to the roller body 126, they are considered to be part of the roller body 126. The centering rod 300 extends at least partially into the threaded hole 131 of one of the threaded blocks 131. As the threaded blocks are fixed to the roller body 126 and the centering locking disc 200 is fixed to the central shaft 122, the centering rod 300 thereby acts to prevent relative rotation of the roller body 126 relative to the central shaft 122. As previously, a hole 128a is formed in the wear plate 128 that is mounted to the roller body 126. The hole 128 in the wear 21 plate 128 and the roller body locking hole 125 allow the centering bolt to be inserted from outside the roller 120, through the threaded block 131, and into a locking hole 202 of the centering locking disc 200 / 400. Figure 10 shows a cutaway perspective view of the roller body 126. In this example, there are no threaded blocks 131. In some known designs of eccentric roller crusher, there is empty space inside the roller body, the empty space being an annular space defined between the central shaft, the first pair of bearings, and an inner side of the roller body. Such known designs of crusher may be retrofitted to include a central locking disc 200,400 as described hereinabove. That is, such a known design of crusher may be retrofitted by the following steps: 1) Mounting a central locking disc 200,400 on the central shaft so that the central locking disc 200,400 is fixed for rotation with the central shaft. a. This may involve tapping holes in the central shaft to receive bolts for mounting the central locking disc 200; 2) Drilling a roller body locking hole 125 in the existing roller body 126, wherein the hole is sized to receive the centering bolt 300 therethrough; a. This may optionally include adding threading to the roller body locking hole 125. 3) Using wear plates that allow access to the roller body locking hole 125 from outside the roller, such as wear plates 128 having a wear plate hole 128a or wear plates 128 that allow access to the roller plate hole 125 between two adjacent wear plates 128. The centering bolt 300 has a length sufficient to simultaneously sit within a locking hole 202 and to bear against a part of the roller body 126 (e.g. a roller body locking hole 125) to thereby prevent relative movement between the roller body 126 and the central locking disc. Together, the central locking disc 200,400 and the centering bolt provide a lock system for an eccentric roller crusher 100. These two parts may also be used when retrofitting an existing eccentric roller crusher. In which case, the precise length of the centering bolt 300 can be selected according to the dimensions of the existing crusher. Figure 11 shows a roller 120 lacking the centering locking disc 200. In this roller, one or more shaft locking holes 212 are formed in the surface of the central shaft 122. These serve the same purpose as the radially-oriented locking holes 202 of the centering locking disc 200, and all features described hereinabove relating to the 22 locking holes 202 of the centering locking disc 200 (e.g. tapered sections etc.) apply equally to the shaft locking holes 212 of Figure 11. In this case, the shaft locking hole 212 depth is the depth of the hole measured from a radially outer surface of the central shaft 122. Figure 12 shows a roller 120 lacking any centering locking disc 200 and lacking any shaft locking holes 212 in the central shaft. Instead, in this example, a first hole 214 is formed in an axial end of the roller 120. A second hole 216 is formed in a component fixed relative to the shaft which, in this case, is a sealing labyrinth mounted on the shaft 122. The first hole 216 is formed in a component fixed relative to the roller which, in this case, is a sealing labyrinth mounted on the roller body 126. In this example, the centering bolt 300 may be inserted through the holes 214,216 to thereby prevent relative rotation of the roller body relative to the central shaft 122. That is, the locking holes are axially-oriented in this example. Figure 13 shows an example in which automated locking means 218 are provided. In the example depicted, the automated locking means 218 are internal to the roller body. The automated locking means 218 is configured to control movement of the centering bolt 300 between a first position and a second position. In the first position, the centering bolt 300 is simultaneously located at least partially within both the roller body locking hole 125 and the shaft locking hole 212 (or shaft locking hole 202, if a centering locking disc 200,400 is present), to prevent relative rotation of the roller body 126 and the central shaft 122. In the second position, which is the position depicted in Figure 13, the centering bolt 300 is not located within at least one of the locking holes and thereby does not prevent relative rotation of the roller body 126 and the central shaft 122. The automated locking means 218 may be electric, magnetic, electromagnetic, or hydraulic. The automated locking means 218 may be provided in any of the examples discussed herein. For example: the automated locking means 218 may be used in example rollers having or not having a centering locking disc 200,400, and / or the automated locking means 218 may be used in example rollers having or not having first and second holes 214,216 formed in an axial end position. In rollers that have the automated locking means 218, it is not essential that the centering rod 300 is accessible from outside the roller 120. Thus, for example, the roller body locking hole may also not be accessible from outside the roller, but may instead be formed purely internally within the roller 120. The automated looking means 218 shown in Figure 13 is mounted on the roller body 126, and the centering bolt 300 is moved radially inward to lock the roller body 126 relative to the central shaft 122. In other examples, not shown, the automated locking means 218 may be mounted on the central shaft 122 instead. In this case, the centering bolt may be moved radially outward to engage with a roller body locking hole. In the example showin in Figure 13, the centering bolt 300 is shown sitting in a locking hole formed in the roller body. However, in an alternative, the centering bolt 300 may be contained entirely within the automated locking means 218 when the cnetering bolt is in the first position. In such cases, it is the automated locking means that provide the roller body locking hole (when the automated locking means are mounted to the roller body) or provide the shaft locking hole (when the automated locking means are mounted to the central shaft). That is, in these examples, the automated locking means 218 provides a component fixed relative to the roller body or to the central shaft. Figure 14 shows a roller 120 having a brake unit. The brake unit includes a brake calliper 250 having one or more brake pads 251 is mounted relative to the roller body 126 and a brake disc 252 that is mounted relative to the central shaft 122. The brake calliper 250 may be activated (e.g. electrically, hydraulically etc.) so as to bias the brake pad 251 against the brake disc 252 and thereby prevent relative rotation of the roller body 126 and the central shaft 122. In other examples, not shown, the brake calliper could be mounted relative to the central shaft 122, and the brake disc may be an annular disc mounted relative to the roller body. In some embodiments, multiple brake callipers 250 may be provided. In other embodiments, only one brake calliper 250 may be provided. In all rollers designs disclosed herein that use a centering bolt 300, a motor (such as the drive mechanism 118 or a separate stepper motor) may optionally be used to incrementally rotate the central shaft 122 within the roller body 126 to bring the or a shaft locking hole into alignment with the centering bolt 300. Thus, in one example, a worker may manually insert a centering bolt 300 through a roller body locking hole and (gently) bias it towards a shaft locking hole. The motor may then rotate the central shaft 122 until the or a shaft locking hole is brought into alignment with the roller body locking hole, at which point the biasing force causes the centering rod 300 to enter the shaft locking hole. This may work either with radially-oriented or axially-oriented locking holes. In cases where the shaft locking hole is located close to a radially-inward end of the roller body locking hole, it may be possible for a worker to visually inspect to see when the locking holes are aligned, as the motor steps the central shaft 122 around its axis, and then insert the centering bolt 300 only once the holes are aligned. In 24 examples using automated locking means 218, the roller 120 may have sensors to detect the relative alignment of the central shaft 122 and the roller body 126, such that the motor can be automatically driven so as to bring the or a shaft locking hole into alignment with the centering bolt 300 before the automated locking means 218 moves the centering bolt 300 to the first (i.e. locked) position. In this manner, activation of the braking means may be entirely automatic, i.e. does not require a worker to be manually inserting the centering bolt 300.
Claims
1. A roller for an eccentric roller crusher, the roller comprising:a central shaft:a roller body mounted for rotation relative to the central shaft; and braking means for preventing rotation of the roller body relative to the central shaft.
2. The roller according to claim 1, comprising:a shaft locking hole that is located either on the central shaft or on a shaft fixed component that is fixed against rotation relative to the central shaft;a roller body locking hole that is located either in the roller body or on a roller fixed component that is fixed against rotation relative to the roller body;wherein the braking means comprises:a centering piece;wherein the centering piece is movable between a first position and a second position,wherein in the first position, the centering piece is simultaneously located at least partially within both the roller body locking hole and the shaft locking hole, to prevent relative rotation of the roller body and the central shaft; andwherein in the second position, the centering piece is not located within at least one of the locking holes and thereby does not prevent relative rotation of the roller body and the central shaft.
3. The roller according to claim 2, wherein the roller body locking hole is an axially-oriented roller body locking hole, and wherein the shaft locking hole is an axially-oriented shaft locking hole on the shaft fixed component.
4. The roller according to claim 2, wherein the roller body locking hole is a radially-oriented roller body locking hole; and wherein the shaft locking hole is a radially-oriented shaft locking hole formed in the central shaft.
5. The roller according to claim 2, wherein the shaft fixed component comprises a centering locking disc;wherein the shaft locking hole is a radially-oriented shaft locking hole formed in the centering locking disc;and wherein the roller body locking hole is a radially-oriented roller body locking hole.
6. The roller according to claim 5, wherein the centering locking disc comprises a plurality of radially-oriented shaft looking holes.
7. The roller according to claim 6, wherein each locking hole includes an outwardly expanding tapered portion at its radially outer side; andoptionally wherein the tapered portion of each locking hole contacts the tapered portions of two adjacent locking holes.
8. The roller according to any of claims 2 to 7, wherein in the second position, the centering piece is removed from the roller body locking hole.
9. The roller according to any of claims 2 to 8, wherein the roller body locking hole is accessible from an outer side of the roller; andoptionally further comprising a removable bolt or removable cover arranged to prevent debris from passing through the roller body locking hole.
10. The roller according to any of claims 2 to 9, wherein the centering piece has a first end and a second end, wherein a portion of the centering piece including the first end has a tapered shape or a pointed end.
11. The roller according to any of claims 2-10, wherein a portion of the centering piece that includes the second end is configured to receive a tool for applying torque to the centering piece.
12. The roller according to any of claims 2-11, the centering piece includes screw threading along at least a portion of its length, optionally wherein an outer diameter of the screw threading is a largest diameter of the centering piece along its length.
13. The roller according to claim 12, wherein the roller body locking hole has roller body locking hole screw threading, wherein the roller body locking hole screw threading is configured to engage with the screw threading of the centering piece: and / orwherein the shaft locking hole has shaft locking hole screw threading, wherein the shaft locking hole screw threading is configured engage with the screw threading of the centering piece.14.The roller according to any of claims 2 to 13, further comprising one or more wear plates mounted to an outer surface of the roller body, andoptionally wherein one or more of the one or more wear plates includes a wear plate hole therethrough or a wear plate cutout section, wherein the wear plate hole or cutout section allows access to the roller body locking hole from the radially outer side of the roller.
15. The roller according to claim 1, wherein the braking means comprises a brake pad, wherein the brake pad is either:a) fixed against rotation relative to the roller body and configured to releasably load against either the central shaft or against a shaft fixed component that is fixed against rotation relative to the central shaft; orb) fixed against rotation relative to the shaft and configured to releasably load against either the roller body or against a roller body fixed component that is fixed against rotation relative to the roller body.16.The roller according to any preceding claim, further comprising automated locking means configured to activate the braking means to prevent relative rotation of the roller body relative to the central shaft, optionally wherein the automated locking means comprises an electrical system and / or a hydraulic system.
17. The roller according to claim 16, when dependent at least upon claim 2, wherein the automated locking means are configured to move the centering piece from the second position to the first position.
18. An eccentric roller crusher comprising: a rocker; and the roller according to any preceding claim.
19. A method of assembling or maintaining an eccentric roller crusher, wherein the eccentric roller crusher comprises the roller according to any of claims 1 -17, the method comprising:1) activating the braking means to prevent relative rotation of the roller body relative to the central shaft;2) optionally, removing one or more wear plates that are mounted on the roller body;3) installing one or more wear plates on the roller body; and4) deactivating the braking means to allow relative rotation of the roller body relative to the central shaft.
20. A lock system for an eccentric roller crusher that comprises a central shaft and a roller body that is mounted for rotation relative to the central shaft, the lock system comprising:a centering locking disc; anda centering piece;wherein the centering locking disc is mountable to the central shaft and fixable against rotation relative to the central shaft;wherein a plurality of radially-oriented locking holes are formed around a circumference of the centering locking disc, each locking hole having a respective locking hole depth in the radial direction of the centering locking disc; andwherein the centering piece is configured to fit into any one of the locking holes, the centering piece having a length defined between a first end and a second end of the centering piece.