AU2020204514A1

AU2020204514A1 - Roller assembly for a conveyor system

Info

Publication number: AU2020204514A1
Application number: AU2020204514A
Authority: AU
Inventors: Colin Fisher
Original assignee: Rotaframe Pty Ltd
Current assignee: Rotaframe Pty Ltd
Priority date: 2019-12-02
Filing date: 2020-07-06
Publication date: 2021-06-17

Abstract

A roller assembly for a conveyor system is disclosed wherein the roller assembly is configured to support a part of a conveyor belt. The roller assembly includes a mounting frame configured to be fixedly attached to a main frame of the conveyor 5 system. A roller support frame is pivotally joined to the mounting frame at a fulcrum, whereby the roller support frame is able to support a first set of rollers and a second set of rollers, wherein the first set of rollers is rotationally offset from the second set of rollers around the fulcrum. The roller support frame is pivotable between a first operative position, wherein the first set of rollers engages and supports the conveyor 10 belt while the second set of rollers is spaced away from the conveyor belt, and a second operative position, wherein the second set of rollers engages and supports the conveyor belt while the first set of rollers is spaced away from the conveyor belt. 2/6 Figure 3 28 32 36 34 26 22 20b 52 28 38 32 20a 3 4 30 40 36 42 50 56 38 Figure 4 24 12 20a 45 50 22 30 44 38 54 56

Description

2/6

Figure 3

28 32 36

34 26 22

20b

52 28

38 32

20a 3

4

30

40 36 42 50 56 38

Figure 4

24

12

20a 45

50 22

30 44 38 54 56

Roller assembly for a conveyor system

TECHNICAL FIELD

The present disclosure relates to a roller assembly for a conveyor system.

More particularly, the present disclosure relates to a roller assembly for a conveyor system allowing easier and safer access to the rollers for maintenance.

BACKGROUND

A traditional belt conveyor system normally has one or more flights of endless conveying belts, wherein each conveying belt moves along rollers supported on a frame. The conveyor system typically includes a head pulley provided at the destination, a tail pulley provided at the source, and a number of carrying idler rollers arranged at spaced intervals between the drive pulley and the tail pulley. The carrying idler rollers support the conveyor belt and the goods carried thereon as the goods are moved from the source to the destination. Once the goods are deposited at the destination, the empty conveyor belt returns to the source. Return idler rollers are installed on the underside of the conveyor to provide support to the returning conveyor belt.

One use of conveyor systems is to transport bulk material, e.g. from a mine site to a transport facility or a processing site. Such conveyor systems often have very long conveyor belts that are laden with heavy ore - they also traverse harsh terrain and are subjected to adverse environmental conditions experiencing extreme temperatures, wind and rain. During operation the carrying and return idler rollers can become worn, damaged or clogged with grit and mud and therefore need to be replaced - this is commonly known in the industry as a change out. If not replaced in time the rollers can seize, which will lead to increased friction between the seized roller and the conveyor belt and subsequently cause damage to the conveyor belt and potentially a fire.

Changing idler rollers in such bulk material conveyor systems is a labour intensive and strenuous task performed by mine site technicians in hot, humid, dusty and noisy conditions. In most instances, the operation of the conveyor system needs to be stopped so that the belt can be lifted away from the idler roller - this is sometimes done in a rather crude manner by simply utilising a crowbar. Other methods include jacking up the conveyor belt on an interim roller so that there is sufficient space beneath the belt for the rollers to be removed e.g. on a scissor jack style belt lifter, with rigging/ cranage or with an electro-hydraulic belt lifter. These methods all have manual handling and body impact / entrapment risks and are common causes of injuries on site. The belt lifter aids are large and awkward to manually carry up flights of stairs and to operate in confined spaces such as narrow raised walkways which are typical on mine sites and remote areas where the conveyor belt traverses gullies, ravines or other undulating ground. It is therefore preferable to provide a way for the maintenance work io to be done using comparatively lightweight basic hand tools and equipment that are easily carried manually.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

SUMMARY OF THE DISCLOSURE

According to the disclosure, there is provided a return roller assembly for a conveyor system wherein the return roller assembly is configured to support a part of a conveyor belt, the return roller assembly comprising a locking frame configured to be fixedly attached to a support frame of the conveyor system; a roller support frame being pivotally joined to the locking frame at a fulcrum, the roller support frame being configured to support a first roller on one side of the fulcrum and to support a second roller on an opposed side of the fulcrum, the roller support frame being able to pivot between a first operative position, wherein the first roller supports the conveyor belt while the second roller is spaced away from the conveyor belt, and a second operative position, wherein the second roller supports the conveyor belt while the first roller is spaced away from the conveyor belt; and a locking mechanism for locking the roller support frame to the locking frame when the roller support frame is selectively in its first or second operative position.

The locking frame may include a distal end member and a proximal end member mountable on respective opposed stringer beams of the conveyor system, the distal and proximal end members being aligned with each other to pivotally support the roller support frame.

The roller support frame may include a shaft being configured to extend transversally across the conveyor belt with two lateral roller support arms provided on opposed ends of the shaft. In one embodiment the shaft defines the fulcrum and the roller support arms are configured to support the first and second rollers. The shaft may include hexagonal protrusions extending axially from opposed ends of the shaft.

The roller support arms may include adjustable threaded bolts respectively associated with each of the first and second rollers, wherein each bolt projects towards and abuts io against its associated roller and is configured to prevent brinelling damage of its roller.

The locking mechanism may be a bolt for bolting the roller support frame to the locking frame when the roller support frame is selectively in its first or second operative position.

The locking mechanism may include two pairs of holes, a first hole of each pair of holes being provided in the locking frame and a second hole of each pair of holes being provided in the roller support frame, wherein each pair of holes is configured to be independently aligned to permit the insertion of the bolt. In one embodiment a first of the pairs of holes are respectively provided approximately midway between the fulcrum and a position at which the first roller is to be supported, while a second of the pairs of holes are respectively provided approximately midway between the fulcrum and a position at which the second roller is to be supported.

BRIEF DESCRIPTION OF DRAWINGS

The above and other features will become more apparent from the following description with reference to the accompanying schematic drawings. In the drawings, which are given for purpose of illustration only and are not intended to be in any way limiting: Figure 1 is a side view of a generic conveyor system; Figure 2 is a perspective view of a lower part of a conveyor system showing a return roller assembly supporting a conveyor belt return, wherein one of the conveyor system's stringer beams has been omitted for clarity; Figure 3 is a perspective view of the return roller assembly of Figure 2 shown in a first operative position; Figure 4 is a side view of the return roller assembly of Figure 2, shown supporting a conveyor belt; Figure 5 is a perspective view of the return roller assembly of Figures 2 to 4 shown in a second operative position; Figure 6 is a side view of the return roller assembly of Figure 5, shown supporting a conveyor belt; Figure 7 is a perspective view of a larger portion of the conveyor system of Figure 2 showing the return roller assembly but also showing a carrying roller assembly supporting a conveyor belt (shown in hashed "transparency" lines for clarity); Figure 8 is a side view of the conveyor system of Figure 7, showing the carrying roller assembly in a first operative position; and Figure 9 is a side view of the conveyor system of Figure 7, showing the carrying roller assembly in a second operative position.

DETAILED DESCRIPTION

Figure 1 shows a generic conveyor system 10 that is typically used in transporting goods or materials between a source and a destination. The conveyor system 10 generally comprises an endless looped conveyor belt 12 arranged to move along various types of rollers. The rollers include a head pulley 14 provided at the destination and a tail pulley 16 provided at the source. Along its upper side, the conveyor system 10 has a plurality of carrying rollers 18 arranged at spaced intervals between the head pulley 14 and the tail pulley 16. Along its lower side, the conveyor system 10 has a plurality of return rollers 20 arranged at spaced intervals between the head pulley 14 and the tail pulley 16. Both the carrying rollers 18 and the return rollers 20 are known as idler rollers in the trade because they are not driven by a motor but merely rotate through frictional contact with the moving conveyor belt 12. Thus, the carrying rollers 18 and return rollers 20 are configured to support the weight of the conveyor belt 12 and of any goods carried on the conveyor belt 12. Generally, due to the increased weight of the conveyor belt 12 and goods, the carrying rollers 18 are spaced more closely together, whereas the return rollers 20 are spaced more sparsely due to only carrying the weight of the conveyor belt 12.

Figure 2 shows a lower part of the conveyor system 10, namely only showing a lower return portion of the conveyor belt 12 that is carried by a return roller 20 mounted in a return roller assembly 22. The return roller assembly 22 is mounted onto a conveyor support frame that typically comprises a pair of parallel elongated stringer beams 24. In Figures 2, 4 and 6 only one of the stringer beams 24 is shown with the opposed (front) stringer beam being omitted so that the underlying return roller assembly 22 can be seen more clearly.

The return roller assembly 22 includes a locking frame configured to be fixedly attached to the stringer beams 24 and a roller support frame being pivotally joined to the locking frame at a fulcrum.

The return roller assembly 22 includes a cylindrical shaft 26 that is joined to the stringer beams 24 by two opposed distal and proximal end members in the form of mounting brackets 28. The opposed mounting brackets 28 cooperate to define the locking frame. Each mounting bracket 28 has a cylindrical sleeve 30 being configured to rotatably receive a respective end of the shaft 26. The sleeve 30 is joined to a mounting plate 32 having bolt holes 34 for being bolted to the stringer beams 24. Each mounting bracket 28 further includes a locking plate 36 located inboard of the mounting plate 32.

The shaft 26 carries two flat roller support arms 38 that are respectively joined to the shaft 26 at or near its opposed ends so that the roller support arms 38 are located adjacent to and inboard of the locking plates 36. The shaft 26 and the roller support arms 38 cooperate to define the roller support frame. The roller support arms 38 and the locking plates 36 can be rigidly bolted together as will be described in due course. The roller support arms 38 are orientated perpendicularly to the shaft 26 and joined thereto approximately midway along their length - in this way the roller support arms 38 function similar to a seesaw with the shaft 26 acting as the fulcrum. It will be appreciated that in the exemplary embodiment the roller support frame is substantially H-shaped in plan view. Towards the opposed outer ends of each roller support arm 38 there are upwardly facing open slots 40 configured to freely receive and locate the opposed ends of an axle 42 of the return rollers 20.

The return roller assembly 22 is therefore arranged to support two return rollers 20, which are respectively referenced with numerals 20a and 20b, wherein the return rollers 20a, 20b are orientated parallel to each other and to the shaft 26 and wherein the return rollers 20a, 20b are rotationally offset from each other by an angle of about 180°. The return roller assembly 22 allows pivoting of the roller support arms 38 and their return rollers 20a, 20b around the fulcrum defined by the shaft 26 so that either of the return rollers 20a, 20b can be selectively brought into contact with the conveyor belt 12.

A hexagonal protrusion 44 extends axially from the shaft 26 for attachment of a spanner or other similar tool (e.g. a socket wrench) to facilitate the above pivoting movement. In some embodiments (see Figure 7), a lever 45 can be mounted on the shaft 26, whereby the lever 45 is configured to be manually manipulated or connected to a pneumatic / hydraulic activation cylinder to assist in pivoting the shaft 26.

Figures 3 and 4 show the return roller assembly 22 being pivoted into a first operative position wherein return roller 20a is in contact with the conveyor belt 12. A locking arrangement is provided to lock the return roller assembly 22 in the first operative position. In this regard, the return roller assembly 22 further includes a first pair of locking holes 46, 48 that are located at a distance approximately midway between the shaft 26 and the return roller 20a. The locking hole 46 extends transversely through the locking plate 36 and the locking hole 48 extends transversely through the roller support arm 38. When the return roller 20a is correctly pivoted into the first operative position, the locking holes 46, 48 align with each other and permit the insertion of a locking bolt 50 that fixedly joins the roller support arm 38 to the locking plate 36 so that the return roller 20a is locked in the first operative position. It will be appreciated that in such configuration the return roller 20b is spaced away from the conveyor belt 12.

Figures 5 and 6 show the return roller assembly 22 being pivoted into a second operative position wherein return roller 20b is in contact with the conveyor belt 12, while return roller 20a is spaced away from the conveyor belt 12. Again, the locking arrangement allows the return roller assembly 22 to be locked in this second operative position. The return roller assembly 22 includes a second pair of locking holes 52, 54 that are located at a distance approximately midway between the shaft 26 and the return roller 20b. The locking holes 52, 54 fulfil the same function as the locking holes 46, 48 so that when the return roller 20b is correctly pivoted into the second operative position, the locking bolt 50 can be inserted therethrough to again fixedly join the roller support arm 38 to the locking plate 36 and lock the return roller 20b in the second operative position.

The locking bolt 50 can be threaded with a corresponding thread provided in the locking holes 48, 54. Alternatively the locking bolt 50 can be held in place by a nut, split pin, circlip or any other suitable equivalent mechanical connection as will be well understood in the art.

It is envisaged that the locking bolt 50 will generally be provided on both lateral sides of the return roller assembly 22, thereby to assist in carrying the weight of the conveyor belt 12 and excessive torque being applied to the shaft 26. However, in cases where the conveyor belt 12 and return rollers 20 are relatively narrow, it may be that locking bolts 50 will be provided on one lateral side of the return roller assembly 22.

The return roller assembly 22 includes anti-brinelling bolts 56 that are joined to and extend through the roller support arms 38. When the return roller 20 is in use and actively supporting the conveyor belt 12 (e.g. roller 20a in Figure 4) its anti-brinelling bolt 56 will be loosened to allow the return roller 20a to freely rotate under movement of the conveyor belt 12. It will be appreciated that in relation to Figure 6 the anti-brinelling bolt 56 will be loosened from return roller 20b. Conversely, when the return the roller 20 is not in use and is spaced away from the conveyor belt 12 (e.g. roller 20b in Figure 4) its anti-brinelling bolt 56 will be tightened to abut against the return roller 20b - typically against its sidewall - thereby to prevent operational vibration from brinelling the bearings of the return roller 20b. It will be appreciated that in relation to Figure 6 the anti-brinelling bolt 56 will be tightened against return roller 20a.

In use, the return roller assembly 22 will be locked in its first operative position whereby the return roller 20a is arranged to support the weight of the conveyor belt 12. When a maintenance inspection is conducted and it is determined that the return roller 20a is damaged or faulty, the return roller 20a can be easily swapped out for operative use of the return roller 20b. This is done by firstly removing the locking bolt 50 from the locking holes 46, 48 to release the roller support arm 38 from the locking plate 36. Subsequently a spanner is attached to the hexagonal protrusion 44 and the shaft 26 is pivoted to lower the return roller 20a away from the conveyor belt 12 while simultaneously bringing the return roller 20b into contact with the conveyor belt 12. Thereafter the return roller assembly 22 is locked its second operative position by inserting the locking bolt 50 through the now aligned locking holes 52,54. In those embodiments comprising the lever 45, it is envisaged that the return roller assembly 22 can be locked in either its first or second operative positions by bolting the lever 45 to its adjacent stringer beam 24.

If it is safe to do so with the conveyor belt 12 still in moving operation, the faulty return roller 20a can be lifted out of the slots 40 and removed for cleaning or repair or replacement with a new return roller. In such case is envisaged that the return roller assembly 22 will be left in its second operative position

Alternatively, if it would be too dangerous to remove the faulty return roller 20a during moving operation of the conveyor belt 12, the return roller 20a can simply be left in place and a maintenance note made that further attention is required. Then when the conveyor system 10 is shut down for other reasons, e.g. its annual shut down cycle, the mine site technician can return and remove and/or replace the return roller 20a.

It will be appreciated that the return roller assembly 22 provides a permanently available secondary/substitute return roller 20 that is immediately available for use and that can be easily interchanged for a faulty return roller. A mine site technician simply requires a first spanner suitable for removing the locking bolt 50 and a second spanner for attachment to the hexagonal protrusion 44 to enable the swapping out of the return rollers, e.g. a single shifting spanner may suffice.

Referring now to Figures 7 to 9, there is shown a larger portion of the conveyor system 10 of Figure 2 showing the return roller assembly 22 but also showing a carrying roller assembly 60 supporting the carrying conveyor belt 12, the latter being shown in hashed "transparency" lines so that the carrying roller assembly 60 can be seen more clearly.

The carrying roller assembly 60 includes a shaft 62 that is joined to the stringer beams 24 by two opposed mounting brackets 64 that are typically bolted to the stringer beams 24. Each mounting bracket 64 has a cylindrical sleeve 66 being configured to rotatably receive a respective end of the shaft 26. Each mounting bracket 64 further has bent off buttress flanges 68, which are orientated to substantially perpendicular to each other forming an enclosed angle of 90° with its vertex being aligned with the shaft 62.

The shaft 62 carries various roller support frames that are configured to carry two sets of transversally aligned carrying rollers 70,72, wherein one carrying roller set 70 is rotationally offset around the shaft 62 from the other carrying roller set 72. The offset angle is sufficient that while one carrying roller set 70 engages the underside of the conveyor belt 12, the other carrying roller set 72 is spaced away from the conveyor belt 12. In the drawings, the two carrying roller sets 70,72 are shown being offset by an angle of about 45°. The offset angle can be varied to increase or decrease the distance that the carrying roller sets 70,72 will be spaced away from the conveyor belt 12 and typically the offset angle will be between 30° and 90°.

io In the exemplary embodiment each carrying roller set 70,72 comprises three carrying rollers 74 arranged in a roughly U-shaped trough when seen in end view wherein the central carrying roller 74 is arranged to extend substantially perpendicularly between the stringer beams 24, while the two outer carrying rollers 74 are inclined thereto. There are thus two outer roller support frames 76 and two inner roller support frames 78. It will be appreciated that other conveyor systems may be provided with more than three rollers in a set and in such case will accordingly require more roller support frames.

The outer roller support frames 76 are substantially triangular in shape seen in side view and lie inboard adjacent to the mounting brackets 64. The outer roller support frames 76 are able to be pivoted between the buttress flanges 68 by rotation of the shaft 62, thereby to move from a first operative position (see Figures 7 and 8) wherein carrying roller set 72 is in abutting contact with the conveyor belt 12, to a second operative position (see Figure 9) wherein carrying roller set 70 is in abutting contact with the conveyor belt 12.

During use, when the carrying conveyor belt 12 is laden with bulk material, the conveyor belt 12 tends to weigh heavily on the carrying rollers 74 and sometimes may wrap partially around the carrying rollers 74. This can make it difficult to rotationally move the shaft 62 to selectively disengage the carrying roller sets 70,72. For this reason a lever 80 is joined to the shaft 62, whereby the lever 80 is configured to be manually manipulated or connected to a pneumatic / hydraulic activation cylinder 82 to assist in pivoting the shaft 62. In some embodiments the cylinder is permanently located in place, whereas in other embodiments the activation cylinder 82 can be connected only when needed. The lever 80 includes a bolt hole 84 therethrough permitting the lever 80 to be selectively bolted to locking holes 86 in the stringer beams 24.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the roller assembly as shown in the specific embodiments without departing from the spirit or scope of the disclosure as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word io "comprise" or variations such as "comprises" or "comprising" is used in a non-limiting and an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in the various embodiments of the drive sub. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements.

Reference numerals

conveyor system 48 locking hole 12 conveyor belt 50 locking bolt 14 head pulley 52 locking hole 16 tail pulley 54 locking hole 18 carrying rollers 56 anti-brinelling bolts return rollers 60 carrying roller assembly 22 return roller assembly 62 shaft 24 stringer beams 64 mounting brackets 26 shaft 66 sleeve 28 mounting brackets 68 buttress flanges sleeve 70 carrying roller set 32 mounting plate 72 carrying roller set 34 bolt holes 74 carrying rollers 36 locking plate 76 outer roller support frames 38 roller support arms 78 inner roller support frames slots 80 lever 42 axle 82 activation cylinder 44 hexagonal protrusion 84 bolt hole lever 86 locking holes 46 locking hole

Claims

1. A roller assembly for a conveyor system wherein the roller assembly is configured to support a part of a conveyor belt, the roller assembly comprising a mounting frame configured to be fixedly attached to a main frame of the conveyor system; a roller support frame being pivotally joined to the mounting frame at a fulcrum, the roller support frame being configured to support a first set of rollers and a second set of rollers, wherein the first set of rollers is rotationally offset from the second set of rollers around the fulcrum, the roller support frame being able to pivot between a first operative position, wherein the first set of rollers engages and supports the conveyor belt while the second set of rollers is spaced away from the conveyor belt, and a second operative position, wherein the second set of rollers engages and supports the conveyor belt while the first set of rollers is spaced away from the conveyor belt; and a locking arrangement provided on the roller support frame for locking the roller support frame in place when the roller support frame is selectively in its first or second operative position.

2. A roller assembly as claimed in claim 1, wherein the mounting frame comprises a distal mounting bracket and a proximal mounting bracket mountable on respective opposed stringer beams of the conveyor system, the distal and proximal mounting brackets being aligned with each other to pivotally support the roller support frame.

3. A roller assembly as claimed in claim 2, wherein the roller support frame comprises a shaft extending transversally between the mounting brackets.

4. A roller assembly as claimed in claim 3, wherein the shaft defines the fulcrum.

5. A roller assembly as claimed in claim 3 or 4, wherein the shaft comprises hexagonal protrusions extending axially from opposed ends of the shaft, whereby in use the hexagonal protrusions are configured to be engaged by a tool for causing rotation of the shaft to pivot the roller support frame between its first or second operative position.

6. A roller assembly as claimed in claim 3 or 4, wherein the shaft comprises a lever joined thereto, whereby in use the lever can be manipulated for causing rotation of the shaft to pivot the roller support frame between its first or second operative position.

7. A roller assembly as claimed in claim 6, further comprising an activation cylinder being joined to the lever.

8. A roller assembly as claimed in any one of claims 1 to 5, wherein the roller support frame comprises adjustable threaded bolts respectively associated with each of roller in the first and second sets of rollers, wherein each bolt projects towards and abuts against its associated roller and is configured to prevent brinelling damage of its roller.

9. A roller assembly as claimed in any one of claims 1 to 8, wherein the locking arrangement comprises a bolt for bolting the roller support frame to the mounting frame when the roller support frame is selectively in its first or second operative position.

10. A roller assembly as claimed in any one of claims 1 to 8, wherein the locking arrangement comprises a bolt for bolting the roller support frame to the main frame of the conveyor system when the roller support frame is selectively in its first or second operative position.

11. A roller assembly as claimed in any one of claims 1 to 10, wherein the first roller set and the second roller set comprise between one and five rollers.

12. A roller assembly as claimed in any one of claims 1 to 11, wherein the first roller set and the second roller set are rotationally offset from each other by an angle of between 30° to 90° when the roller support frame is configured to support a carrying part of the conveyor belt.

13. A roller assembly as claimed in claim 12, wherein the first roller set and the second roller set are rotationally offset from each other by an angle of about 45°.

14. A roller assembly as claimed in any one of claims 1 to 11, wherein the first roller set and the second roller set are rotationally offset from each other by an angle of about 180° when the roller support frame is configured to support a return part of the conveyor belt.