GB2288133A - Moment restoring clamping device - Google Patents

Abstract

An apparatus for breaking-up a supply of raw material comprises a frame, a shaft 34 rotatably mounted in said frame, a plurality of annular working elements 40 removably mounted on said shaft, first and second shaft mountings 38, 39, a removable support 32 forming part of the second shaft mounting 39 and which can be withdrawn from a supporting position with respect to one end of the shaft to permit removable and/or installation of elements 40 and an adjustable clamping device 41 mounted on the frame at the other end of the shaft, in which the clamping device is adjustable between a release position in which it allows the shaft to be driven when the shaft is supported by the first and second shaft mountings, and a clamping position in which the clamping device can apply a restoring moment, to said other end of the shaft to compensate for and to allow withdrawal of the removable support 32 whereby the annular elements 40 can be installed and/or demounted by axial movement over the one end of the shaft. <IMAGE>

Description

CRUSHER/SHREDDER APPARATUS WITH REMOVABLE WORKING ELEMENTS This invention relates to a crusher or shredder apparatus having a frame, at least one drive shaft rotatably mounted in said frame, a plurality of annular working elements removably mounted on said shaft, first and second shaft mountings provided on the frame to support the shaft, a drive mechanism coupled with one end of said shaft at or near to said first shaft mounting, and a removable support forming at least part of said second shaft mounting and which can be removed from a supporting position with respect to an opposite end of said shaft to permit removal and/or installation of said elements with respect to the shaft.

Crusher apparatus and shredder apparatus are used to break down a supply of raw materials to required smaller size, and necessarily have to be of robust construction to withstand the loads generated in service. Crusher apparatus may be used to break down raw material in the form of rock or stone (mineral) supply to form aggregate (gravel) of required size, whereas shredder apparatus are used more commonly for breaking down domestic and industrial waste material to smaller size to render the material more readily disposable, eg on landfill sites.

Common to both types of apparatus is the use of annular working elements mounted along the length of massive drive shafts, mounted parallel to and closely adjacent to each other, and raw materials supplied to the apparatus undergoes a crushing or shredding action which breaks down the size of the raw material.

Inevitably, over a period of time, the working parts and surfaces of the working elements become worn and/or damaged, and especially when hard materials are being treated, and therefore replacement of the working elements becomes necessary.

The annular working elements are usually slid longitudinally of the drive shafts, during mounting and de mounting, and this requires the elements to be moved to and from one end of the shaft while the normal shaft mounting for this shaft end is removed temporarily.

With existing designs of apparatus, this requires the use of a temporary prop to take part of the load of the shaft, while the shaft mounting is being removed, and also while the shaft end remains unsupported, in view of the massive load of the shaft and its working elements. Evidently, without use of a temporary prop, the shaft would be supported solely at the drive end, and usual bearing support at the drive end would be incapable of withstanding the applied turning moment generated by the unsupported mass of the shaft and working elements projecting from the bearing support.

The use of a temporary prop, in existing designs of crusher or shredder apparatus, will now be described with reference to Figure 1 of the accompanying drawings, which shows a schematic side view of a drive shaft and annular working elements mounted thereon, and which will usually cooperate with an adjacent set of working elements on a parallel and closely spaced further drive shaft (s).

The frame of the apparatus is not shown in detail, but includes support for shaft mountings 10 and 11, which are carried by side plates of the frame and which each support rotatably a respective one of the two opposed ends 12, 13 of drive shaft 14. Annular working elements 15, eg crusher or shredder discs, are mounted along the length of shaft 14, and cooperate with adjacent elements of a further drive shaft (s) to carry out working operations on a raw material supply, eg to crush minerals into aggregate in the case of a crusher apparatus, or to shred domestic or industrial waste in the case of a shredder apparatus.

A gear box 16 is carried by the frame of the apparatus and houses a drive gear 17, eg a crown wheel which is coupled drivingly with shaft end 12. Bearing assemblies 18 and 19 support the shaft ends 12 and 13 respectively, and once the drive shaft has been installed in the frame, the shaft end 12 will usually remain substantially permanently mounted in, and supported by bearing assembly 18, whereas the opposite shaft end 13 is supported by a removable end frame 20 which carries bearing assembly 19.

Therefore, when it is desired to replace unduly worn or damaged elements 15, bearing assembly 19 is removed from support of shaft end 13 to allow axial withdrawal of the elements 15 in a direction towards shaft end 13, and to allow installation of replacement elements in the opposite direction.

However, before bearing assembly 19 can be removed, it is usually necessary to apply temporary support, eg by use of a prop, to support an intermediate region of the shaft 14, as shown schematically by reference A. This allows end frame 20 to be removed, usually by movement axially away from shaft end 13, which then withdraws support for the shaft end 13 by bearing assembly 19. The elements 15 can then be slid axially along shaft 14 (after release from their respective seatings on the shaft). However, evidently it will be only the elements 15 which are located to the right of temporary support A, ie between support A and the now free unsupported shaft end 13 which can be slid off the shaft, whereas the elements 15 within the region of the temporary support, and between the support and shaft end 12, will remain on the shaft and be incapable of being removed. Therefore, after removal of a first set of the elements 15, it is usually necessary to reintroduce support for shaft end-13, as shown schematically by support B, followed by removal of temporary support A, and which then allows at least some of the remainder of the elements 15 to be slid axially to the right towards shaft end 13. Temporary prop 18 is then reintroduced, and support B withdrawn, which then allows at least some of the remainder of the elements 15 to be removed.

In practice, in many cases the interchange of the support A and B has to be carried out more than twice, both during demounting of the elements, and also again during reassembly with replacement elements where necessary.

The present invention therefore seeks, by relatively simple mechanical means, to provide an improved mounting of a drive shaft in a crusher or shredder apparatus, allowing simplified demounting and installation of the annular working elements, and without need to use a temporary intermediate prop to support the drive shaft intermediate its shaft ends.

According to the invention there is provided an apparatus for breaking-up a supply of raw material and comprising: a frame; a drive shaft rotatably mounted in said frame; a plurality of annular working elements removably mounted on said shaft; first and second shaft mountings provided on the frame to support the shaft; a drive mechanism coupled with one end of said shaft at or near to said first shaft mounting; a removable support forming at least part of said second shaft mounting and which can be withdrawn from a supporting position with respect to an opposite end of said shaft to permit removal and/or installation of said elements with respect to the shaft; and an adjustable clamping device mounted on said frame in the region of said one end of the shaft, said clamping device being adjustable between a release position in which it allows the shaft to be driven by the drive mechanism when the shaft is supported by the first and second shaft mountings, and a clamping position in which the clamping device can apply a restoring moment, directly or indirectly, to said one end of the shaft to compensate for and to allow withdrawal of the removable support whereby the annular elements may be installed and/or demounted by axial movement over said opposite end of the shaft.

Thus, by use of a simple means, namely the clamping device, the removable support forming the second shaft mounting for the opposite end of the shaft can be removed and thereby leave the shaft end free for withdrawal and/or installation of the annular elements along the shaft, in that the turning moment which would otherwise have to be borne by the first shaft mounting by reason of the now cantilever assembly of shaft and annular elements is in fact resisted by the restoring moment applied to said one shaft end by the clamping device.

In a preferred arrangement, the clamping device makes a direct clamping engagement with a drive gear of the drive mechanism, said gear being coupled directly with said one shaft end.

The clamping device may comprise a saddle which can be adjusted downwardly to engage an upper surface of the drive gear, and thereby apply the required restoring moment to the shaft end via the drive gear.

In addition, if the clamping device is designed to be capable of making a mating fit with the teeth of the drive gear, then the clamping position of the clamping device also will function to lock the drive gear (and therefore also the shaft) against rotation, which will be desirable during installation and removal of the annular elements.

Additionally, or alternatively, a clamping device may be adjustably mounted at or near to said one shaft end, and to be adjustable upwardly from a release position to a clamped position of engagement, eg directly with said one shaft end, but inboard, ie axially inwardly of the first shaft mounting so as to apply a required restoring moment to the shaft.

Still further, as an addition, further addition, or alternative, a clamping device may be mounted on the frame to be adjustable downwardly from a release position to a clamped position by pulling downwardly (directly or indirectly) on said one shaft end.

A preferred embodiment of apparatus according to the invention will now be described in detail, by way of example only, with reference to Figures 2, 3, 4a and 4b of the accompanying drawings, in which: Figure 2 is a schematic side illustration of part of a crusher/shredder apparatus according to the invention; Figure 3 is a detailed view, to an enlarged scale, showing in more detail the construction and operation of an adjustable clamping device which can be used to facilitate mounting and demounting of annular working elements with respect to a drive shaft of the apparatus; and Figures 4a and 4b are, respectively, detailed illustrations, similar to Figure 3, showing, respectively, clamped positions and release positions with respect to a drive gear mounted on a projecting end of the drive shaft.

Referring now to Figures 2 to 4, there is shown a single drive shaft of a crusher or shredder apparatus, and having annular working elements mounted thereon, and usually there will be at least one further drive shaft and related working elements located closely adjacent thereto, and to cooperate therewith in order to carry out the necessary breaking down operation on the raw material supply.

In the case of a crusher apparatus, the raw material supply may comprise rock or minerals, which are required to be broken down to smaller size, whereas in the case of a shredder apparatus, the raw material supply may comprise industrial or domestic waste.

The apparatus is designated generally by reference 30 and comprises a main frame (not shown in detail), and having side frame elements in which a first shaft mounting 31 and a second shaft mounting 32 are mounted, to support, respectively, one end 33 of a drive shaft 34 and an opposite end 35 of the drive shaft. The shaft end 33 comprises the drive input end of the drive shaft, in that a drive mechanism is coupled with shaft end 33 at or near to the first shaft mounting 31, and in the illustrated embodiment comprises a drive gear 36 in the form of a crown wheel.

The second shaft mounting 32, which normally provides support for the opposite shaft end 35, is formed at least partly by a removable support comprising removable end frame 37. A bearing assembly 38 is carried by first shaft mounting 31, and provides a vertical support, and also rotary mounting for the drive shaft end 33, whereas bearing assembly 39 which is carried by second shaft mounting 32 provides a similar function for the opposite shaft end 35. However, bearing assembly 38 normally remains fixed, whereas bearing assembly 39 can be withdrawn from support of the shaft end 35 upon axial withdrawal of end frame 37.

A plurality of axially spaced annular working elements 40 is mounted along the length of drive shaft 34, and may comprise any suitable design of crusher discs or shredder discs, known per se, depending upon whether apparatus 30 is a crusher apparatus or a shredder apparatus respectively. Inevitably, in view of the arduous nature of the working operations, the working elements 40 become subject to wear and damage over relatively short periods of time and therefore regular maintenance is required, as well as repair on site. This therefore requires the working elements 40 to be withdrawn from the drive shaft 34, and then reinstalled together with replacement elements where necessary. The preferred embodiment disclosed herein provides, by use of a simple means, a facility whereby the removable end frame 37 can be withdrawn to leave the shaft end 35 free for withdrawal and installation of the annular elements, in that the turning moment applied to the first shaft mounting 31 by the now cantilever assembly of drive shaft 34 and the annular elements 40 (in the absence of support for unsupported shaft end 35) can be resisted by a restoring moment applied to the drive shaft end 33 by a simple clamping device which will be described in more detail below.

Thus, an adjustable clamping device is mounted on the frame, in the region of the drive shaft end 33, and as shown in Figure 2 by the detail referenced generally by reference numeral 41, and which is shown to an enlarged scale in Figures 3, 4a and 4b. The clamping device 41 is adjustable between a release position, as shown in Figure 2 and Figure 4b, in which it allows the drive shaft 34 to be driven by the drive mechanism (gear 36) when the shaft 34 is supported by the first and second shaft mountings 31 and 32, and a clamping position as shown in Figure 4a. In the clamping position, the clamping device 41 applies a restoring moment, directly or indirectly, to the drive shaft end 33 to compensate for, and to allow withdrawal of the removable support frame 37 whereby the annular working elements 40 can be installed and/or demounted by axial movement over the opposite shaft end 35.

In the illustrated embodiment, the clamping device can be adjusted downwardly to make direct clamping engagement with an upper surface of the drive gear of the drive mechanism, and thereby apply an anti-clockwise restoring moment to the drive shaft 34, as seen in Figure 2. The clamping device 41 comprises a saddle 42 which can be adjusted downwardly, from the release or unclamped position shown in Figure 4b, to the clamped position shown in Figure 4a, in which it makes clamping engagement with the facing teeth of the drive gear 36, and which also locks the drive gear 36 against rotation. Saddle 42 is curved to a radius corresponding with the curvature of the drive gear, and is carried by a square cross-section mounting block 43 welded to the top face of saddle plate 42, and guided to move non-rotatably between two guide plates 44.

The clamping device 41 comprises a saddle assembly comprising a large adjusting screw 45 which turns through a screwed block 46 welded into a casing cover 47 of a gear box forming part of the drive mechanism and in which drive gear 36 is also mounted. The lower end of the adjusting screw 45 is a free fit in the saddle plate 42, which is secured onto the screw 45 by a mounting plate 48 and screws 49, as shown in Figure 3.

Therefore, rotation of adjusting screw 45 allows saddle plate 42 to be raised and lowered between the release and the clamping positions, and when in the release position, it is well clear of the gear 36 to allow the drive shaft 34 to be driven by the drive mechanism, whereas when it is lowered to the clamping position, it firmly clamps the top of the drive gear 36 and both locks it against rotation, but also applies the required restoring moment to the shaft to compensate for the cantilever load applied to the first shaft mounting 31 when the shaft end 35 is no longer supported, for the purposes of mounting and demounting the annular working elements.

Although not shown, additionally, or alternatively, a clamping device may be adjustably mounted on the frame, at or near to the drive shaft end 33, and to be adjustable upwardly from a release position to a clamped position of engagement, eg directly with the drive shaft end 33, ie axially inwardly of the first shaft mounting 31 so as to apply the required (anticlockwise) restoring moment to the drive shaft 34 when shaft end 35 is unsupported.

Still further, although not illustrated, as an addition, further addition, or alternative, a clamping device may be mounted on the frame, near to the drive shaft end 33, and to be adjustable downwardly from a release position to a clamped position, and in the clamped position to be capable of pulling downwardly (directly or indirectly) on the drive shaft end 33 to apply and anti-clockwise restoring moment.

Claims (6)

I CLAIMS

1. An apparatus for breaking-up a supply of raw material and comprising: a frame; a drive shaft rotatably mounted in said frame; a plurality of annular working elements removably mounted on said shaft; first and second shaft mountings provided on the frame to support the shaft; a drive mechanism coupled with one end of said shaft at or near to said first shaft mounting; a removable support forming-at least part of said second shaft mounting and which can be withdrawn from a supporting position with respect to an opposite end of said shaft to permit removal and/or installation of said elements with respect to the shaft; and an adjustable clamping device mounted on said frame in the region of said one end of the shaft, said clamping device being adjustable between a release position in which it allows the shaft to be driven by the drive mechanism when the shaft is supported by the first and second shaft mountings, and a clamping position in which the clamping device can apply a restoring moment, directly or indirectly, to said one end of the shaft to compensate for and to allow withdrawal of the removable support whereby the annular elements may be installed and/or demounted by axial movement over said opposite end of the shaft.

2. Apparatus according to Claim 1, including a direct clamping engagement between the clamping device and said drive mechanism, and comprising a drive gear of the drive mechanism which is coupled directly with said one shaft end.

3. Apparatus according to Claim 1, in which said clamping device comprises a saddle which is adjustable downwardly to engage an upper surface of a drive gear of said drive mechanism, thereby to apply the required restoring moment to the shaft end via said drive gear.

4. Apparatus according to Claim 2, in which said clamping device comprises a saddle which is capable of making a mating fit with the teeth of a drive gear of said driving mechanism, thereby to lock said drive gear against rotation.

5. Apparatus according to Claim 1, in which said clamping device is adjustably mounted at or near to said one shaft end, and is adjustable upwardly from a release position to a clamped position of engagement with said one shaft end, axially inwardly of the first shaft mounting so as to apply a required restoring moment to the shaft.

6. Apparatus according to Claim 1, in which said clamping device is mounted on the frame to be adjustable downwardly from a release position to a clamped position by.

pulling downwardly on said one shaft end.