Patent Description:
Some material processing devices include a rotor to which an operator may be exposed, particularly during maintenance, thereby risking injury or death. For example, an impact crusher includes a crushing rotor located in a crushing chamber. In use, rotation of the rotor causes material, e.g. rocks, within the chamber to be crushed against crushing surfaces within the chamber until they are small enough to fit through a gap beside the rotor. Traditionally, if the crusher jams the operator has to access the crushing chamber to clear the jam. Should the rotor rotate when the crusher is open, rocks may be flung from the crusher causing injury, or the operator may become trapped by the rotor. In some instances, it is necessary for the operator to manually rotate the drum in order to free a blockage or for other maintenance purposes, e.g. replacing a wearable component such as a blade or wear plate, which may also expose the operator to danger if the crusher is open. For example, operators have been known to stand on the rotor to try to rotate it with their weight and this may result in injury or death. Document <CIT> describes a conventional material processing apparatus with a worm and worm wheel arrangement, according to the preamble of claim <NUM>.

It would be desirable therefore to provide an apparatus in which unwanted rotation of the rotor is prevented while still allowing purposeful rotation.

From a first aspect, the invention provides a rotor rotation device for controlling rotation of a rotor of a material processing device, the rotor rotation device comprising: a drive mechanism; and means for selectively coupling the drive mechanism to the rotor, wherein said rotor rotation device is operable in a driving state in which said coupling means couples the drive mechanism to the rotor to allow rotation of said rotor by said drive mechanism, or in a non-driving state in which said coupling means does not couple the drive mechanism to the rotor, and wherein said drive mechanism comprises a worm shaft and corresponding worm wheel, said coupling means being configurable to selectively couple said worm wheel to said rotor. Typically said worm shaft comprises at least one worm, preferably only one worm.

In preferred embodiments, said drive mechanism comprises a slewing drive mechanism comprising said worm shaft and corresponding worm wheel in the preferred form of a slewing ring.

Said slewing drive mechanism typically comprises a hub, typically an annular hub, on which said slewing ring is rotatably supported, typically by one or more bearings.

Typically, said slewing ring provides an interface by which said rotor may be selectively coupled to the drive mechanism, wherein said interface may comprise a side of the slewing ring, or an annular plate coupled to a side of the slewing ring.

In preferred embodiments, said worm shaft and said worm wheel are mutually configured to prevent back-driving of said worm shaft by said worm wheel, wherein the mutual configuration typically comprises a friction angle between a worm of the worm shaft and the worm wheel being larger that a lead angle of the worm.

In preferred embodiments, said coupling means is configured to selectively couple the drive mechanism to a rotatable shaft that is part of, or coupled to, the rotor and is rotatable about a first axis, and wherein said drive mechanism has a rotational drive axis that is coincident with said first axis in use, and wherein, preferably, said rotation drive axis corresponds to the rotational axis of said worm wheel.

Typically, said rotor includes a rotor shaft, and said rotatable shaft may be said rotor shaft or a stub shaft coupled to and coaxial with said rotor shaft, or an extension of said rotor shaft.

In preferred embodiments, said coupling means comprises a drive-engaging portion that is connected or connectable to the drive mechanism, and a rotor-engaging portion that is configured for releasable coupling with said rotor. Said drive-engaging portion may be connected or connectable to said worm wheel. The drive-engaging portion may comprise at least one support structure configured for connection with the worm wheel, conveniently to an exposed side of the worm wheel or to an exposed cover fixed to a side of the worm wheel, and for supporting the rotor-engaging portion.

Said drive-engaging portion may comprise a hub, which may be plate-like in form and/or may be disc-shaped.

Said rotor-engaging portion may be configured to releasably interlock with said rotatable shaft such that rotation of said rotor-engaging portion is imparted to said rotatable shaft. Optionally, said rotor-engaging portion has at least one male or female interlocking formation configured to interlock with at least one corresponding female or male interlocking formation provided on said rotatable shaft, and/or wherein said rotor-engaging portion and said rotatable shaft are correspondingly shaped for interlocking. Optionally, said rotor-engaging portion is movable into and out of engagement with said rotatable shaft in an axial direction.

Optionally, said rotor-engaging portion is configured to interlock with said rotatable shaft in only one relative rotational orientation of said rotor-engaging portion and said rotatable shaft.

Optionally, said rotor-engaging portion and said rotatable shaft are each provided with a respective corresponding key formation, the corresponding key formations being configured to allow said rotor-engaging portion is configured to interlock with said rotatable shaft in only one relative rotational orientation of said rotor-engaging portion and said rotatable shaft.

Optionally, said rotor-engaging portion is configured to interlock with said rotatable shaft in a plurality of relative rotational orientations of said rotor-engaging portion and said rotatable shaft. Said rotor-engaging portion and said rotatable shaft may each be provided with a plurality of corresponding spline formations, the spline formations preferably being circumferentially spaced-apart around a respective portion of said rotor-engaging portion and said rotatable shaft, and preferably extending in an axial direction.

Optionally, said rotor-engaging portion may comprise any one of: a locking device; a locking pin, a projection or a socket.

Optionally, said rotatable shaft comprises a projecting portion or a socket portion for engaging with said rotor-engaging portion.

Optionally, said rotor-engaging portion is separately formed from said drive-engaging portion, and is configured for releasable interconnection with said drive-engaging portion. Said drive-engaging portion may be shaped to define an aperture through which said rotor-engaging potion extends when interconnected with said drive engaging portion.

Alternatively, said rotor-engaging portion may be integrally formed with, or permanently fixed to, said drive engaging portion, and preferably projects perpendicularly from said drive engaging portion.

Optionally, said drive-engaging portion can be connected to the drive mechanism in either one of a first orientation in which said rotor-engaging portion extends towards said rotor, or a second orientation in which said rotor-engaging portion extends away from said rotor.

Optionally, said drive-engaging portion and said rotor-engaging portion are configured such that, when said drive-engaging portion is connected to said drive mechanism, said rotor-engaging portion extends along an axis that is co-axial with the rotational axis of said rotatable shaft.

Said drive mechanism typically has a body that is shaped to define an aperture, and when said drive-engaging portion is connected to said drive mechanism, said rotor-engaging portion preferably extends into and optionally though said aperture of said body.

In preferred embodiments, said drive mechanism has a body that is shaped to define an aperture, and wherein when said drive-engaging portion is connected to said drive mechanism, said rotatable shaft extends into and optionally though said aperture of said body.

Typically, said drive mechanism includes, or is connectable to, a device for driving said drive mechanism, wherein the driving device may comprising a powered driving device or a manually operated driving device.

Optionally, the device includes a bearing hub for connecting said drive mechanism to said material processing device, wherein said bearing hub is coupled to said drive mechanism and rotatably supports said rotatable shaft.

From another aspect, the invention provides a material processing apparatus comprising a material processing device supported by a chassis or base, and the rotor rotating device of the first aspect of the invention coupled to said material processing device for controlling rotation of the rotor of the material processing device. Typically, a rotatable shaft connected to said rotor is supported by a bearing mount, said rotor rotating device being coupled to said bearing mount and to said rotatable shaft. Typically, said drive mechanism comprises a body that supports said worm shaft and said worm wheel, and wherein said body is coupled to said bearing mount and said worm wheel is coupled to said rotatable shaft.

In preferred embodiments, said material processing device includes or is connectable to drive means for rotating said rotor in normal use of said material processing device, said drive means being coupled to a driven end of said rotor, and wherein said rotor rotating device is coupled to a non-driven end of said rotor.

In some embodiments, said material processing device is a crusher, optionally an impact crusher.

Advantageously, the rotor rotation device is operable in a driving state in which it may be used to effect controlled (e.g. in terms of speed and/or angular displacement) rotation of the rotor (preferably in either rotational direction). This facilitates maintenance of the crusher (or other material processing device), e.g. to help clear a blockage or provide access to parts of the rotor or chamber that are otherwise difficult to access. Advantageously, the worm drive mechanism cannot be back-driven by the rotor as a result of which the worm drive mechanism serves as a brake or lock against unwanted or uncontrolled rotation of the rotor. Typically, the primary drive mechanism of the crusher (or other material processing apparatus (i.e. the primary drive mechanism that is typically provided in addition to the rotor rotation device) is disabled or disconnected, as required, when the rotor rotational device is in use.

Embodiments of the invention are now described by way of example and with reference to the accompanying drawings in which like numerals are used to denote like parts and in which:.

Referring now in particular to <FIG> of the drawings, there is shown, generally indicated as <NUM>, a material processing apparatus. Only those parts of the apparatus <NUM> that are helpful for understanding the present invention are shown and described. In general, the apparatus <NUM> may be configured to perform any one or more of a plurality of material processing tasks, such as feeding, screening, separating, crushing, milling, waste recycling or demolition and/or washing, on one or more types of aggregate or other material, for example rocks, stones, gravel, sand and/or soil, or any other material that is quarried, mined or excavated. To this end, the apparatus <NUM> includes a material processing device <NUM> configured to perform the relevant material processing task(s). Embodiments of the invention are suited for use with a variety of different types of material processing device, in particular those that include a rotor, for example crushers (in particular impact crushers), shredders and milling devices. The rotor may be a material processing component, e.g. the crushing rotor of an impact crusher, or may be a rotary operating device. For example, in the case of an impact crusher, a shredder or a milling device, the rotor may comprise a rotatable drum or other rotatable structure which may have one or more blades, teeth or other formations to facilitate the respective material processing operation, whereas in the case of a jaw crusher the rotor may comprise a rotary operating device that is rotated to effect movement of a crushing jaw. In the embodiment illustrated and described herein, the material processing device <NUM> is a crusher, in particular an impact crusher. It will be understood however that the invention is not limited to impact crushers or crushers in general and that the same or similar description applies to other material processing devices as would be apparent to a skilled person.

The apparatus <NUM> is typically but not necessarily mobile and so may be provided on a chassis <NUM>. The chassis <NUM> may carry one or more other components that facilitate use of the crusher <NUM>, usually a feed assembly <NUM> for delivering material to the crusher <NUM> and one or more conveyors <NUM> for transporting crushed or uncrushed material, e.g. for the purposes of stockpiling. The feed assembly <NUM> may comprise a hopper and/or a screen. In a typical arrangement, material deposited into the hopper is graded by the screen as a result of which some of the material (usually the larger pieces that do not pass through the screen) is fed to the crusher <NUM> while the rest bypasses the crusher <NUM> and is directed elsewhere, e.g. to a conveyor.

The powered components of the apparatus <NUM>, including the crusher <NUM>, are typically powered by a power system which may include one or more hydraulic system comprising motor(s), actuator(s) and/or an internal combustion engine and/or other components as required. It will be understood that alternative power systems, e.g. electrical or pneumatic power systems, may be used, and so the motor(s) and other components may be powered by alternative means. An electrical system may also be provided as would be apparent to a skilled person. In the illustrated embodiment, the apparatus <NUM> includes power plant <NUM> for generating the requisite power (e.g. including electrical, hydraulic and/or pneumatic power as applicable) for the apparatus <NUM>. The power plant <NUM> may take any convenient conventional form, e.g. comprising any one or more of an engine, e.g. an internal combustion engine, electric motor(s), compressor and/or batteries.

In embodiments in which the apparatus <NUM> is mobile one or more wheels and/or tracks <NUM> are provided on the chassis <NUM>. The apparatus <NUM> may be self-propelled and to this end the power plant <NUM> usually comprises an internal combustion engine. In such cases, the internal combustion engine conveniently generates power for the hydraulic system(s), e.g. by operating the hydraulic pump(s) (not shown), and may also power an electric generator (not shown) for the electrical system, and/or may drive, directly or indirectly, the crusher <NUM>.

Referring now to <FIG>, an exemplary embodiment of the crusher <NUM> is shown schematically. The crusher <NUM> includes a rotor <NUM> comprising a rotatable drum <NUM> (or other rotatable structure), which may include projections <NUM> (often referred to as blow bars) or other formations on its outer surface to facilitate crushing. The rotor <NUM> includes a shaft <NUM> on which the drum <NUM> (or other rotatable structure) is mounted. The shaft <NUM> and/or the drum <NUM> are rotatable about an axis A1 (<FIG>), which is typically horizontally disposed in use, in at least one but preferably both rotational directions. The drum <NUM> and shaft <NUM> may be rotatable together about the axis A1 (i.e. the shaft <NUM> is rotatable), or the drum <NUM> may rotate about the shaft (i.e. the shaft <NUM> is fixed). The rotor <NUM> is located in a crushing chamber <NUM>, and is rotatable within the chamber <NUM> about axis A1. One or more impact aprons <NUM> may be provided in the chamber <NUM> to provide impact surface(s) against which material may be crushed. The apron(s) <NUM> are typically movable (e.g. pivotable about pivot points P in the illustrated example) in order to adjust the spacing between the apron <NUM> and the rotor <NUM> in order to adjust the crushing operation. The apron(s) <NUM> may be moved using any convenient actuating mechanism (not shown). In use, material (not shown) to be crushed is fed into the chamber <NUM> via inlet <NUM> and, as the rotor <NUM> rotates, the material is thrown back and forth between the rotor <NUM> and other internal surfaces within the chamber <NUM> (e.g. the internal wall(s) of the chamber <NUM> and/or the impact surface(s) of the apron(s)), which has the effect of crushing the material. When the material has been crushed into small enough particles, it exits the chamber <NUM> via outlet <NUM>, typically under the influence of gravity. The chamber <NUM> may have one or more hatch, door or removable panel, which may be opened to allow access to the inside of the chamber <NUM>, e.g. for the purposes of maintenance.

In normal use, the rotor <NUM> is driven (rotated) by a powered drive system (not shown), which may for example be powered by the power plant <NUM>. The powered drive system may take any conventional form. For example, the drive system may for example comprise a motor, e.g. a hydraulic motor, mounted at an end of the rotor <NUM> and being operable to rotate the rotor <NUM>. Alternatively, or in addition, the drive system may comprise an internal combustion engine, or other drive mechanism, coupled to the rotor <NUM>, e.g. by a belt and pulley system (not shown) having a driven pulley on the rotor <NUM> and driving pulley on the drive shaft of the motor/engine. The powered drive system is used to drive the material processing device <NUM> when performing its normal function, e.g. crushing in the illustrated example.

Referring now in particular to <FIG>, there is shown a first rotor rotating device <NUM> embodying the invention. Advantageously, the rotor rotating device <NUM> is provided in addition to the powered drive system in order to rotate the rotor <NUM> in circumstances other than the normal use of the material processing device <NUM>. Also shown in <FIG> is part of the material processing device <NUM> to which the rotor rotating device <NUM> is coupled in use, which in preferred embodiments comprises part of the rotor shaft <NUM>, typically an end part. The rotor shaft <NUM> is rotatably supported in a bearing mount <NUM>. In alternative embodiments, e.g. in which the shaft <NUM> is not rotatable, any other suitable rotating part of the rotor <NUM> may be rotatably supported by the bearing mount <NUM>, e.g. a shaft, sleeve or other structure that is connected to and rotatable with the rotor <NUM>. Typically, the end of the shaft <NUM> (or other rotating part) supported by the bearing mount <NUM> is the non-driven end. In alternative embodiments (not illustrated), the device <NUM> may be coupled to a shaft/bearing mount at the driven end. The shaft <NUM> (or other rotating part) extends from the chamber <NUM>, typically along axis A1, and may be located in a housing <NUM>. The bearing mount <NUM> is fixed with respect to the chamber <NUM>. The bearing mount <NUM> may be mounted (directly on indirectly) on the chassis <NUM> or other base/structure that supports the material processing device <NUM>. The bearing mount <NUM> may be of any suitable conventional type, e.g. comprising ball bearings, roller bearings or any other conventional bearing arrangement, that allows the shaft <NUM> (or other rotating part) to rotate (about axis A1 in this example).

In typical embodiments, a stub shaft <NUM> is connected to the end of the shaft <NUM> (or other rotating part). The stub shaft <NUM> projects outwardly from the bearing mount <NUM>, typically along the rotational axis of the shaft <NUM> (i.e. axis A1 in the illustrated example). The stub shaft <NUM> may be fixed to the shaft <NUM> by any convenient fixing means (e.g. screws <NUM> in the illustrated example) and rotates with the shaft <NUM>. The stub shaft <NUM> serves as an extension of the shaft <NUM> and provides a rotatable part with which the rotor rotating device <NUM> selectively interacts, as is described in more detail hereinafter. In alternative embodiments, the end of the shaft <NUM> (or other rotating part) may project outwardly from the bearing mount <NUM>, in which case the stub shaft <NUM> may be omitted since the projecting end of the shaft <NUM> (or other rotating part) can provide the rotatable part with which the rotor rotating device <NUM> selectively interacts.

In use, the rotor rotating device <NUM> is coupled to, or otherwise fixed with respect to, the bearing mount <NUM>, and is selectively coupled to the rotor <NUM> in order to rotate the rotor <NUM> when coupled thereto. The preferred arrangement is that the device <NUM> is mounted (directly or indirectly) on, or otherwise supported by, the bearing mount <NUM>. Alternatively, the device <NUM> may be mounted on, or supported by, another part of the material processing device <NUM> or apparatus <NUM>. In either case, the rotor rotating device <NUM> is arranged such that it can selectively couple with the rotor <NUM> (in particular the shaft <NUM>, stub shaft <NUM> or other rotatable part as applicable) in order to rotate the rotor <NUM> when required.

The rotor rotating device <NUM> comprises a drive mechanism <NUM> for selectively rotating the rotor <NUM>. Advantageously, the drive mechanism <NUM> comprises a worm drive mechanism. The worm drive mechanism <NUM> comprises a worm shaft <NUM> and a corresponding worm wheel <NUM> (also called a worm gear). The worm shaft <NUM> comprises a worm, being a screw-shaped formation which may be referred to as a gear in the form of a screw, or a worm screw. Corresponding gear formations, or teeth, are provided around the worm wheel <NUM> which intermesh with the worm of the worm shaft <NUM>. The worm acts as a driver for the worm wheel <NUM> whereby rotation of the worm shaft <NUM> about its longitudinal axis causes rotation of the worm wheel <NUM>. Typically, the configuration is such that the worm shaft <NUM> can drive the worm wheel <NUM> in both rotational directions, i.e. rotation of the worm shaft <NUM> in one direction causes the worm wheel <NUM> to rotate in a first direction, while rotation of the worm shaft <NUM> in the other direction causes the worm wheel <NUM> to rotate in a second direction opposite to the first direction. The rotational axis of the worm wheel <NUM> (which is coincident with axis A1 in preferred embodiments) is perpendicular to the longitudinal axis of the worm shaft <NUM>. The worm shaft <NUM> may be rotated by any convenient drive means (not shown), which may be manually operable (e.g. comprising a handle or other manual operating device) or power operable (e.g. comprising a motor, for example a hydraulic or electric motor). In preferred embodiments, the worm drive mechanism is a slewing drive mechanism, and the worm wheel <NUM> is a slewing ring, as is described in more detail hereinafter. Alternatively, other conventional types of worm drive mechanism, e.g. comprising a worm gearbox, may be used. While the worm wheel <NUM> may be referred to as a worm gear, the term "worm gear" may also be used to refer to the combination of the worm shaft and worm wheel.

Advantageously, the worm drive mechanism <NUM> is configured such that the worm wheel, or slew ring, <NUM> is not able to drive the worm shaft <NUM>, i.e. to prevent back driving. This may be achieved by designing the drive mechanism <NUM> such that the coefficient of friction between the worm wheel or slewing ring <NUM> and the worm is larger than the tangent of the worm's lead angle, i.e. that the friction angle between the worm and the worm gear is larger than the worm's lead angle. Because the worm shaft <NUM> cannot be back driven by the worm wheel <NUM>, the drive mechanism <NUM> may be said to be self-locking. To facilitate self-locking, it is preferred that the worm comprises a single helix (which is sometimes referred to as a single-start worm). Advantageously, the drive mechanism <NUM> provides a large speed reduction and high torque multiplication from input to output. Moreover, the drive mechanism <NUM> can provide a relatively high reduction ratio in a relatively compact structure compared to, for example, a circular gear and bevel gear transmission. Advantageously, the drive mechanism <NUM> has a high load capacity and can provide reliable rotational positioning of the rotor <NUM>.

The rotor rotating device <NUM> comprises a body <NUM> that supports the drive mechanism <NUM>, typically being configured to house the worm shaft <NUM> and worm wheel <NUM>. In preferred embodiments where the drive mechanism <NUM> is a slewing drive mechanism, the slewing ring <NUM> is rotatably supported by the body <NUM>. The body <NUM> typically comprises a housing <NUM> in which the slewing ring <NUM> is rotatably located, typically being supported by one or more bearing to facilitate rotation. The housing <NUM> may include an annular plate <NUM> (sometimes referred to as a top plate) or other cover that is fixed to the slewing ring <NUM> and rotates with the slewing ring <NUM>. The plate <NUM> is exposed to serve as an interface by which other components may be connected to the slewing ring <NUM>, and to this end may include sockets or apertures for receiving bolts screws or other fixings. Alternatively, the side of the slewing ring <NUM> may itself be exposed as an interface for connection to other components. The slewing ring <NUM> is typically located coaxially around a hub <NUM>, which typically comprises an inner ring, and about which the slewing ring <NUM> is, usually, rotatable. The hub <NUM> may be part of, or located in, the housing <NUM> as is convenient, and is fixed with respect to the body <NUM>. One or more bearings <NUM> are typically provided between the slewing ring <NUM> and the hub <NUM> to facilitate rotation of the slewing ring <NUM>. In preferred embodiments, the body <NUM> is annular, defining a central aperture <NUM> through which the rotational axis of the slewing ring <NUM> extends. The worm shaft <NUM> is typically also supported by the body <NUM>, and may be incorporated into the housing <NUM>.

In use, the body <NUM> is coupled to, or otherwise fixed with respect to, the bearing mount <NUM>. The preferred arrangement is that the body <NUM> is mounted (directly or indirectly) on, or otherwise supported by, the bearing mount <NUM>. Alternatively, the body <NUM> may be mounted on or supported by another part of the material processing device <NUM> or apparatus <NUM>. The preferred arrangement is such that the axis A1 passes through the aperture <NUM>, preferably being coincident with the rotational axis of the slewing ring <NUM>. Preferably, the arrangement is such that the shaft <NUM>, stub shaft <NUM> or other relevant rotatable part, as applicable, is at least aligned with, and preferably extends into, the central aperture <NUM> of the body <NUM> (as can best be seen from <FIG>).

In the illustrated embodiment, the rotor rotating device <NUM>, and in particular the body <NUM>, is coupled to the bearing mount <NUM> by a fixed bearing hub <NUM>. The bearing hub <NUM> is annular, defining a central aperture <NUM>, and has one end <NUM> fixed to the bearing mount <NUM> and the opposite end <NUM> fixed to the body <NUM>. The preferred arrangement is such that the aperture <NUM> is aligned with the aperture <NUM>, and axis A1 extends through the apertures <NUM>, <NUM>. In the illustrated embodiment, the end <NUM> comprises an annular flange <NUM> that is fixed to the bearing mount <NUM> around the rotor shaft <NUM> by any convenient fixing means, e.g. bolts or screws <NUM>. The opposite end <NUM> may be fixed to the hub <NUM> by any convenient fixing means, e.g. bolts or screws <NUM>. Typically, primary and secondary shaft seals <NUM>, <NUM> are fitted between the stub shaft <NUM> and the bearing hub <NUM>.

The preferred arrangement is such that the shaft <NUM>, stub shaft <NUM> or other relevant rotatable part, as applicable, extends through the bearing hub <NUM> (and may be rotatably supported by the bearing hub <NUM> in any conventional manner), preferably projecting from the end <NUM> such that its free end is located within the central aperture <NUM> of the body <NUM> (as can best be seen from <FIG>).

The rotor rotating device <NUM> includes means for selectively coupling the drive mechanism <NUM> to the rotor <NUM>. In particular, the selective coupling means is configured to selectively couple the slewing ring <NUM> to the shaft <NUM>, stub shaft <NUM> or other rotatable part as applicable, to enable the drive mechanism <NUM> to rotate the rotor <NUM> when required. In preferred embodiments, the selective coupling means comprises a drive-engaging portion and a rotor-engaging portion, which may be integrally form with each other, or separately formed and inter-engageable. The drive-engaging portion is configured for connection to the slewing ring <NUM> (e.g. via plate <NUM> if present), and the rotor-engaging portion is configured for connection to the shaft <NUM>, stub shaft <NUM> or other rotatable part as applicable.

As illustrated in the embodiment of <FIG>, the rotor-engaging portion may comprise a locking device <NUM> configured to interlock with the stub shaft <NUM>. The stub shaft <NUM> and the locking device <NUM> may be configured to interlock in any convenient manner, e.g. being provided with one or more corresponding male and female interlocking formation(s), or by being mutually shaped for male-to-female interlocking connection. In preferred embodiments, the interlocking is such that rotation of the locking device <NUM> (about its axis that is coincident with A1 in the illustrated example) causes corresponding rotation of the stub shaft <NUM> and therefore of the rotor <NUM>, i.e. that the locking device <NUM> and shaft <NUM> cannot rotate relative to each other. It is preferred however that the interlocking does not prevent the locking device <NUM> from being moved into engagement with or out of engagement with the stub shaft <NUM> (which involves movement in the axial direction A1 in the illustrated example).

Optionally, the stub shaft <NUM> and the locking device <NUM> are shaped or otherwise configured to fit together and interlock in only one relative rotational orientation. This may be achieved in any convenient manner, e.g. by configuring the male and female interlocking formation(s) such that they only allow interlocking in one relative rotational orientation, or by shaping the stub shaft <NUM> and the locking device <NUM> such that they only allow interlocking in one relative rotational orientation. For example, in the embodiment of <FIG>, the locking device <NUM> comprises a locking pin having a key formation <NUM> (male or female). The stub shaft <NUM> is shaped to define a socket <NUM> for receiving the locking pin <NUM>, the socket including a corresponding key formation <NUM> (female or male) such that the locking pin <NUM> can only be inserted into the socket <NUM> in one rotational orientation. Alternatively, the locking device <NUM> may be shaped to define a socket, and the stub shaft <NUM> may be shaped to define a pin or other projection that fits into the socket. In either case, the preferred arrangement is such that the locking device <NUM> can be moved into and out of engagement with the shaft <NUM> in the axial direction (along axis A1 in the illustrated example) and, when engaged, there is rotational interlocking between the shaft <NUM> and the locking device <NUM>. Conveniently, the key formations <NUM>, <NUM> serve to provide the rotational interlock between the locking device <NUM> and the stub shaft <NUM>.

The locking device <NUM> is removably engagable with the stub shaft <NUM>. When engaged, the interlocking between the locking device <NUM> and stub shaft <NUM> couples the drive mechanism <NUM> to the rotor <NUM> and allows the rotor <NUM> to be rotated by the device <NUM>. When the locking device <NUM> is disengaged, there is no coupling between the drive mechanism <NUM> and the rotor <NUM> such that the rotor <NUM> cannot be rotated by the device <NUM>. It will be understood that in alternative embodiments in which the stub shaft <NUM> is not present, the foregoing description applies to the rotor shaft <NUM> or other relevant rotatable part, as applicable and as would be apparent to a skilled person.

As illustrated in the embodiment of <FIG>, the drive-engaging portion may comprise one or more support structure <NUM> configured for connection with the slewing ring <NUM> and for supporting the rotor-engaging portion <NUM> (at least when the rotor-engaging portion <NUM> is engaged with the stub shaft <NUM> (or other relevant rotatable part as applicable)). The support structure <NUM> is conveniently connected (releasably or permanently) to the exposed side of the slewing ring <NUM> (or plate <NUM> if present). The preferred arrangement is such that the exposed side of the slewing ring <NUM> (or plate <NUM> if present) faces away from the rotor <NUM>.

In the embodiment of <FIG>, the support structure <NUM> comprises a locking hub, which may be plate-like in form, and which may be disc-shaped. The locking hub <NUM> may be fixed to the slewing ring <NUM> by any convenient fixing means, e.g. screws <NUM> or the like, or may be integrally formed with the slewing ring <NUM>. For example, as illustrated in <FIG>, the hub <NUM> may be shaped and dimensioned to cover the exposed side of the slew ring <NUM> (or plate <NUM>) and to be fixed thereto around the respective peripheries.

The support structure <NUM> may be configured to support the locking device <NUM> in any convenient manner. In the embodiment of <FIG>, the support structure <NUM> and locking device <NUM> are formed separately and can be releasably interconnected. For example, the support structure <NUM> may include an aperture <NUM> through which the locking device <NUM> may be inserted, the locking device <NUM> including one or more formation (e.g. flange <NUM>) by which it may be releasably connected to the structure <NUM> by any convenient fixing means, e.g. screws bots or the like, when the locking device <NUM> is inserted into the aperture <NUM>. Optionally, the aperture <NUM> includes a key formation <NUM> that corresponds to the key formation <NUM> on the locking device <NUM> so that the locking device <NUM> can only pass through the aperture <NUM> in one rotational orientation, e.g. when the key formations <NUM>, <NUM> are aligned. Typically, the support structure <NUM> is fixed to the slewing ring <NUM> after which the locking device <NUM> is inserted though the aperture <NUM> and fixed to the support structure <NUM>. In embodiments where the key formation <NUM> is present, the slewing ring <NUM> may need to be rotated to align the key formation <NUM> with the corresponding key formation <NUM> of the stub shaft <NUM> so that the locking device <NUM> is correctly rotationally aligned with the stub shaft <NUM> when it is inserted through the aperture <NUM>.

An alternative embodiment of the rotor rotating device <NUM> is shown in <FIG> in which like numerals are used to denote like parts and in respect of which the same or similar description applies, unless otherwise indicated, as is provided in relation to the first rotor rotating device <NUM> as would be apparent to a skilled person.

The rotor rotating device <NUM> is substantially the same as the rotor rotating device <NUM> except that alternative means for selectively coupling the drive mechanism <NUM> to the rotor <NUM> are provided. In particular, the stub shaft <NUM> (or shaft <NUM> or other relevant rotational part as applicable) and the locking device <NUM> are configured to interlock in any one of a plurality of relative rotational orientations. This may be achieved in any convenient manner, e.g. by providing each component <NUM>, <NUM> with a respective plurality of corresponding male and female interlocking formations, or by having engagable portions that are shaped for male-to-female interlocking connection in a plurality of relative rotational orientations (e.g. providing the engageable portions with a corresponding regular polygonal transverse cross-section). In the embodiment of <FIG>, the respective engaging portion of the shaft <NUM> and of the locking device <NUM> is provided with a plurality of corresponding spline formations <NUM>, <NUM>' that inter-engage to provide the required rotational interlock when the respective engaging portions are inter-engaged. Preferably, the spline formations <NUM>, <NUM>' are provided around the periphery of the respective engaging portion (typically circumferentially), and preferably extend in a longitudinal direction (parallel with axis A1 in the present example). The number relative rotational orientations in which the shaft <NUM> and locking device <NUM> can be interlocked is determined by the number of spline formations provided, or the pitch between the spline formations. As illustrated in <FIG>, the engaging portion of the locking device <NUM> may comprise a socket <NUM> while the engaging portion of the shaft <NUM> may comprise a corresponding pin <NUM> or other projection shaped and dimensioned to fit the socket <NUM>. Alternatively, the engaging portion of the stub shaft <NUM> may comprise the socket while the engaging portion of the locking device comprises the corresponding pin or other projection.

Optionally, the locking device <NUM> is integrally formed or permanently fixed to the support structure <NUM>, which may be the same or similar to the support structure <NUM>. Alternatively, the locking device <NUM> and support structure <NUM> may be separately formed and releasably interconnectable, for example in the same or similar manner to the locking device <NUM> and support structure <NUM>.

With reference in particular to <FIG>, in preferred embodiments the support structure <NUM> and locking device <NUM> can be connected to the drive mechanism <NUM> in either one of a locking orientation (<FIG>) or a non-locking orientation (<FIG>). In the locking orientation, the locking device <NUM> engages with the stub shaft <NUM> as described above. In the non-locking orientation, the locking device <NUM> projects away from the stub shaft <NUM> and does not engage with the stub shaft <NUM>. Conveniently, adopting the locking or non-locking orientation is achieved by fixing the support structure <NUM> to the drive mechanism <NUM> in either one of two orientations, i.e. a first orientation in which the locking device <NUM> projects from the support structure <NUM> in a direction towards the shaft <NUM> (<FIG>), and a second orientation in which the locking device <NUM> projects from the support structure <NUM> in a direction away from the shaft <NUM> (<FIG>).

In preferred embodiments, when the support structure <NUM>, <NUM> is connected to the slewing ring <NUM> the locking device <NUM>, <NUM> is aligned with the axis A1 and projects from the support structure <NUM>, <NUM> to allow it to engage with the stub shaft <NUM>, <NUM> (unless it is in the non-locking orientation). Typically, the locking device <NUM>, <NUM> extends into, and optionally through, the aperture <NUM> (as can best be seen from <FIG> and <FIG>). In typical embodiments, the locking device <NUM>, <NUM> and stub shaft <NUM>, <NUM> engage in the central aperture <NUM>, although in alternative embodiments they may engage outside of the aperture <NUM> depending on, for example, the respective lengths of the locking device <NUM>, <NUM> and the stub shaft <NUM>, <NUM>. When interconnected, the support structure <NUM>, <NUM> and locking device <NUM>, <NUM> together connect the slewing ring <NUM> to the stub shaft <NUM>, <NUM> to allow rotation of the slewing ring <NUM> to be transmitted to the rotor <NUM>.

In use, when it is desired for the crusher <NUM> to operate normally, the rotor rotating device <NUM>, <NUM> is configured to adopt a non-driving state in which the drive mechanism <NUM> is not coupled to the rotor <NUM> such that the rotor <NUM> is free to be rotated by the drive mechanism of the crusher <NUM>. In the embodiment of <FIG>, the support structure <NUM> may remain fixed to the slewing ring <NUM> and the non-driving state may be achieved by removing or not installing the locking device <NUM>. In the embodiment of <FIG>, the non-driving state may be achieved by fixing the support structure <NUM> to the slewing ring <NUM> in its non-locking orientation. When it is desired to use the rotor rotating device <NUM>, <NUM> to control the rotation of the rotor <NUM> (e.g. during maintenance of the crusher <NUM>), the rotor rotating device <NUM>, <NUM> is configured to adopt a driving state in which the drive mechanism <NUM> is coupled to the rotor <NUM> such that rotation of the slewing ring <NUM> is transmitted to the rotor <NUM>. In the embodiment of <FIG>, with the support structure <NUM> fixed to the slewing ring <NUM>, to adopt the driving state the locking device <NUM> is inserted through the support structure <NUM> into interlocking engagement with the stub shaft <NUM>, and is fixed to the support structure <NUM>. In the embodiment, of <FIG>, the driving state is adopted by installing the support structure <NUM> and locking device <NUM> assembly in its locking orientation.

In the driving state, the rotor rotation device <NUM>, <NUM> may be used to effect controlled (e.g. in terms of speed and/or angular displacement) rotation of the rotor <NUM> (preferably in either rotational direction). This facilitates maintenance of the crusher <NUM>, e.g. to help clear a blockage or provide access to parts of the rotor <NUM> or chamber <NUM> that are otherwise difficult to access. Advantageously, because the drive mechanism <NUM> cannot be back-driven by the rotor <NUM>, the drive mechanism <NUM> serves as a brake or lock against unwanted or uncontrolled rotation of the rotor <NUM>. Typically, the drive mechanism of the crusher <NUM> (i.e. the primary drive mechanism that is typically provided in addition to the device <NUM>, <NUM>) is disabled or disconnected, as required, when the rotor rotational device <NUM>, <NUM> is in use.

In preferred embodiments, a position sensor <NUM>, <NUM> is provided for detecting if the rotor rotation device <NUM>, <NUM> is in the driving state when the rotor rotational device <NUM>, <NUM> is operational. The sensor <NUM>, <NUM> may be configured to detect whether or not the locking device <NUM>, <NUM> is interlocked with the stub shaft <NUM>, <NUM>. Any suitable conventional sensor type may be used for this purpose, e.g. a mechanical switch type sensor, an electrical field sensor, magnetic field sensor, light sensor, ultrasonic sensor, or other contact or non-contact sensor. Preferably, the sensor <NUM>, <NUM> is a wireless sensor to facilitate providing it on rotatable components as required. The sensor <NUM>, <NUM> may be configured to detect the locking device <NUM>, <NUM> (or a specific part thereof) only when the locking device <NUM>, <NUM> is in its interlocking position with the stub shaft <NUM>, <NUM>. For example, in the case of a contact sensor, the sensor <NUM>, <NUM> may be positioned to make contact with the locking device <NUM>, <NUM> (or a specific part thereof) only when the locking device <NUM>, <NUM> is in its interlocking position. In the case of a non-contact sensor, the sensor <NUM>, <NUM> may be positioned and calibrated to detect the locking device <NUM>, <NUM> (or a specific part thereof) only when the locking device <NUM>, <NUM> (or the specific part thereof) is in the sensor's detection field. In the embodiment of <FIG>, the sensor <NUM> is a contact sensor that is mounted on the support structure <NUM> and positioned to make contact with a formation (not visible) on the locking device <NUM> only when the locking device <NUM> is fixed to the structure <NUM> as described above. In the embodiment of <FIG>, the sensor <NUM> may be a contact or non-contact sensor and is provided on the body <NUM> and configured to detect the presence or absence of the locking device <NUM>. When the rotor rotating device <NUM>, <NUM> is in use, if the output of the sensor <NUM>, <NUM> indicates that the device <NUM>, <NUM> is not in the driving state, then the device <NUM>, <NUM> may be configured to activate one or more alert(s) (e.g. activate visual and/or audio alarms) and/or to disable at least part of the operation of the device <NUM>, <NUM> and/or issue an output signal to a remote device that controls the operation of the crusher <NUM>, e.g. to disable the crusher if required. The device <NUM>, <NUM> may be provided with any suitable controller (not shown) for cooperating with the sensor <NUM>, <NUM> (which may for example be the same controller that controls the operation of the device <NUM>, <NUM>), and/or the sensor <NUM>, <NUM> may be in communication with an external controller (not shown).

Claim 1:
A material processing apparatus (<NUM>) comprising:
a crusher;
a powered drive system for rotating a rotor (<NUM>) of said crusher to perform a crushing function and a rotor rotating device (<NUM>) coupled to said crusher for controlling rotation of the rotor (<NUM>) during maintenance of said crusher, the rotor rotation device comprising:
a drive mechanism (<NUM>); and
means for selectively coupling (<NUM>,<NUM>) the drive mechanism (<NUM>) to the Z r rotor (<NUM>), wherein said rotor rotation device (<NUM>) is operable in a driving state in which said coupling means (<NUM>,<NUM>) couples the drive mechanism (<NUM>) to the rotor to allow rotation of said rotor by said drive mechanism, or in a non-driving state in which said coupling means (<NUM>,<NUM>) does not couple the drive mechanism to the rotor, and wherein said drive mechanism comprises a worm shaft (<NUM>) and corresponding worm wheel (<NUM>), said coupling means being configurable to selectively couple said worm wheel to said rotor, and characterized in that said worm shaft and said worm wheel are mutually configured to prevent back-driving of said worm shaft (<NUM>) by said worm wheel (<NUM>).