shaft

Abstract

A non-rotating conveyor belt shaft (40) adapted to support a rotating conveyor belt roller (3) The shaft (40) includes a substantially elongate main body portion (41), and an end portion (42, 43) provided at each end of said main body portion (41). Each end portion (42, 43) is configured to attach a respective end of said shaft (40) to a support frame structure (5) whilst also providing support to said conveyor belt roller (3) via a bearing (20). Said main body portion (41) of said shaft (40) is of a geometrical shape which is substantially non-circular in cross-section or of any other solid shape which is formed with at least one hole, perforation or cutout (56, 66) therethrough.

Description

SHAFTField of the invention

[0001] The present invention relates to a non-rotating shaft which is adapted to support a rotating element. The present invention has particular application to, but is not limited to, being used as a non-rotating idler shaft to support a conveyor idler roller in a conveyor belt system.

[0002] The present invention further relates to a method of manufacturing the shaft.Background of the invention

[0003] Any reference in this specification to prior art, or matter which is said to be known, is not to be taken as an acknowledgement or admission that such prior art or matter forms part of the common general knowledge in the field of the invention to which this specification relates.

[0004] Non-rotating shafts are used in a variety of applications, including as idler shafts in conveyor belt systems.

[0005] As illustrated in figure 1 , a typical conveyor belt system 1 , incorporates one or more drive pulleys 2 and a plurality of idler rollers 3. Each drive pulley 2 is connected to a motor, which when rotated, causes the drive pulley 2, and in turn, the conveyor belt 4, to move. Idler rollers 3 are typically positioned in spaced apart relationship to support the conveyor belt 3. The idler rollers 3 are not driven but rather freely rotate to support the conveyor belt 4 and any materials being conveyed thereon.

[0006] In figure 2 is illustrated a typical prior art cylindrical-shaped idler shaft 10. Each idler roller 3 is typically configured to be supported on the cylindrical-shaped nonrotating bar or shaft 10. This non-rotating shaft 10 spans the width of the conveyor roller 3, and typically includes a bearing arrangement 20 on either end thereof, which allows an idler roller 3 to freely rotate about the non-rotatable idler shaft 10 with the movement of the conveyor belt 4.

[0007] As illustrated in figure 2, the bearing arrangement 20 may typically include the bearing 21 provided within a bearing housing 22, a seal 23, and end shield 24, and a circlip 25 which retain the bearing components in position on the end of the idler shaft 10.

[0008] Whilst existing idler shafts function adequately, they are traditionally manufactured of steel, and consequently they are quite heavy in weight. This has various drawbacks, including OHS issues when the shafts are manually handled.

[0009] In seeking to reduce the weight of the idler shaft, idler shafts are sometimes now manufactured as “hollow shafts” rather than being solid, or, are made with lighter weight non-metallic materials, such as glass fibre reinforced plastics (GFRP).Summary of the invention

[0010] The present invention seeks to provide an alternative shaft which overcomes at least some of the disadvantages of prior art shafts.

[0011] The present invention also seeks to provide a shaft for supporting a rolling component therearound, but which is not of traditional cylindrical shape.

[0012] The present invention also seeks to provide an alternative and improved idler shaft for a conveyor belt system.

[0013] The present invention also seeks to provide an alternative and improved idler shaft which is of reduced weight compared with traditional idler shafts, whilst still satisfying predetermined structural design criteria.

[0014] The present invention also seeks to provide a method by which the alternative shaft design of the present invention may be manufactured.

[0015] The present invention also seeks to provide a method by which the shaft of the present invention may be created by a material removal process technique being applied to a standard / prior art shaft.

[0016] In a broad form, the present invention provides a non-rotating conveyor belt shaft adapted to support a rotating conveyor belt roller, the shaft including: a substantially elongate main body portion; and, an end portion provided at each end of said main body portion, wherein each end portion is configured to attach a respective end of said shaft to a support frame structure whilst also providing support to said conveyor belt roller via a bearing; wherein, said main body portion of said shaft is of a geometrical shape which is substantially non-circular in cross-section or of any other solid shape which is formed with at least one hole, perforation or cutout therethrough.

[0017] Preferably, said shaft is configured to be of minimal weight and satisfy said predetermined structural design criteria, said criteria including any one or combination of: minimising deflection of said main body portion between the end portions of the shaft; minimising deflection of the shaft intermediate, between or beneath the bearings; maximising the second moment of area; maximising the area moment of inertia; maximising the second moment of inertia (MOI); minimising the cross-sectional area of the main body portion of the shaft; and, minimising the volume of material of the main body portion of the shaft.

[0018] Preferably, said main body portion of said shaft is designed to be of a geometrical shape which includes any one of: any solid shape which is substantially non-circular in cross-section; any hollow shape which is substantially non-circular in cross-section; a substantially rectangular shape; an I-beam shape; and / or, any solid shape which is formed with at least one hole, perforation or cutout at least partway therethrough.

[0019] Preferably, at least said main body portion of said shaft is at least partly formed of: a metal material, such as steel or aluminium, or an alloy thereof; a non-metal material, such as a plastics material; a glass fibre reinforced plastics (GFRP) material.

[0020] Preferably, said shaft is configured as a conveyor belt idler shaft.

[0021] In a further broad form, the present invention provides a method of manufacturing a conveyor belt shaft as claimed in any one of the preceding claims, including the steps of: supplying a body of material; and, removing, by milling, shaving, grinding, or otherwise removing at least a portion of said body of material.

[0022] Preferably, in said removing step, said material is removed to form holes, orifices, slits, or cutouts from said body of material.

[0023] Preferably, said removing step is performed by a computer controlled machine.

[0024] Preferably, said removing step is performed according to an algorithm which calculates the minimum weight of the body whilst satisfying said predetermined design criteria.

[0025] Preferably, said predetermined design criteria includes any one or combination of: minimising deflection between the end portions of the shaft; minimising deflection of the shaft intermediate, between or beneath the bearings; maximising the second moment of area; maximising the area moment of inertia; maximising the second moment of inertia (MOI); minimising the cross-sectional area of the main body portion of the shaft; and, minimising the volume of material of the main body portion of the shaft.

[0026] Preferably, said shaft is an idler shaft of a conveyor belt roller.Brief description of the drawings

[0027] The present invention will become more fully understood from the following detailed description of preferred but non-limiting embodiments thereof, described in connection with the accompanying drawings, wherein:

[0028] Figure 1 illustrates a typical conveyor system, showing the provision of idler rollers configured to support a conveyor belt;

[0029] Figure 2 details and exploded view of one end of a typical prior art idler shaft which is configured to support an idler roller therearound via a bearing on each end of the idler shaft;

[0030] Figure 3 illustrates a typical prior art cylindrical-shaped idler shaft used to support an idler roller of a conveyor belt system;

[0031] Figure 4 illustrates an example embodiment of an idler shaft in accordance with the present invention;

[0032] Figure 5 illustrates yet a further example embodiment of an idler shaft of the present invention; and,

[0033] Figure 6 illustrates another alternative example embodiment of an idler shaft of the present invention.Detailed description of preferred embodiments

[0034] The following description of preferred embodiments is provided to illustrate the invention and is not intended to limit the scope of the claims.

[0035] Throughout this specification, like numerals will be used to identify like features, except where expressly otherwise indicated.

[0036] Figures 4 to 6 illustrate various example embodiments of an idler shaft in accordance with the present invention.

[0037] Referring to Figure 4, an example embodiment of a non-rotating shaft 40 in accordance with the present invention is shown. The shaft 40 is adapted to support a rotating element, such as a conveyor belt roller 3, via a bearing 20 at each end of the shaft 40. The shaft 40 includes a substantially elongate main body portion 41 and end portions 42 and 43 provided at each end of the main body portion 41. The end portions 42 and 43 are configured to attach the respective ends of the shaft 41 to a support frame structure, such as a conveyor belt framework 5, whilst also providing support to the rotating element 3 via the bearings 20.

[0038] The main body portion 41 of the shaft 40 is designed to be of minimal weight whilst satisfying predetermined structural design criteria. Such design criteria may include considerations, such as, but not limited to any one or combination of: minimising deflection between the end portions 42 and 43 of the shaft 40, minimising angular deflection of the shaft intermediate, between, or beneath the bearings 20, maximising the second moment of area, maximising the area moment of inertia, maximising the second moment of inertia (MOI), minimising the cross-sectional area of the main body portion 41 of the shaft 40, and / or minimising the volume of material of the main body portion 41 of the shaft 40.

[0039] In this example embodiment, the main body portion 41 of the shaft 40 is designed to be of a geometrical shape which is substantially non-circular in cross-section, such as a somewhat rectangular shape with curved upper and lower portions and flat side portions. This shape maintains a high second moment of area to minimise the deflection of the shaft 10 under load, whilst also reducing the cross-sectional area and the volumeof material of the main body portion 41 of the shaft 40, which reduces the weight and improves manoeuvrability.

[0040] This substantially rectangular shape transitions to a conventional cylindrical shape towards the ends of the shaft 40 at transition areas 44 and 45 to facilitate the attachment of the bearings 20 to the circular cross-section end portions 42 and 43 of the shaft 40.

[0041] The shaft 40 may be at least partly formed of a metal material, such as steel or aluminium, or a non-metal material, such as a plastics material or a glass fibre reinforced plastics (GFRP) material. The choice of material may depend on various factors, such as the required strength, stiffness, durability, corrosion resistance, and cost of the shaft 40. The shaft 40 may be formed by any suitable manufacturing process, such as extrusion, casting, forging, or machining.

[0042] Referring to Figure 5, yet a further example embodiment of a non-rotating shaft 50 in accordance with the present invention is shown. In this embodiment, the main body portion 51 of the shaft 50 is designed to be of a geometrical shape which is partially hollowed out with a plurality of holes 56, cutouts, orifices or the like therein. This shape provides similar advantages as the hollow rectangular shape described above, retaining the strength and stiffness of the main body portion 51 of the shaft 50.

[0043] Referring to Figure 6, another alternative example embodiment of a nonrotating shaft 60 in accordance with the present invention is shown. In this embodiment, the main body portion 61 of the shaft 60 is designed to be of a geometrical shape which has an elongate cutout 66 therethrough. This shape maintains a high area moment of inertia, which reduces the deflection of the shaft 60 under load. This shape with the elongate cutout 66 also reduces the cross-sectional area and the volume of material of the main body portion 61 of the shaft 60, which reduces the weight, the amount and the cost of the material used to make up the shaft 60. This shape also facilitates the attachment of the bearings 20 to the end portions 62 and 63 of the shaft 60.

[0044] It will be appreciated that the above-described embodiments are only examples of possible implementations of the invention, and that various modifications and variations may be made without departing from the scope of the invention as defined in the appended claims.

[0045] For example, whilst the aforementioned embodiments particularly describe the configuration of an idler shaft for a conveyor belt system, it should be understood thatthe invention should not be limited thereby. In particular, the shaft of the present invention may encompass applications beyond idler shafts.

[0046] More broadly, the present invention relates to a non-rotating shaft adapted to support a rotating element, such as a sprocket, pulley, gear, roller or the like. The shaft includes a body having a longitudinal axis and an outer surface, and a plurality of bearing elements arranged circumferentially at the ends of the shaft and / or around the outer surface of the body. The bearing elements are configured to engage with an inner surface of the rotating element and allow relative rotation between the shaft and the rotating element.

[0047] In some embodiments the shaft further includes a locking element that is movable between a first position, in which the locking element allows the rotating element to be mounted on or removed from the shaft, and a second position, in which the locking element prevents axial movement of the rotating element along the shaft. The locking element may be a spring-loaded pin, a threaded bolt, a wedge, a clamp, a snap ring, or any other suitable device.

[0048] In some embodiments the bearing elements are ball bearings, roller bearings, needle bearings, or any other suitable type of bearings. The bearing elements may be fixedly attached to the shaft, or may be detachably mounted on the shaft by means of a retainer, a cage, a sleeve, a ring, or any other suitable structure.

[0049] Throughout this specification, unless the context requires otherwise, the word “comprise”, and any variations thereof such as “comprises” or “comprising”, are to be interpreted in a non-exhaustive sense.

Claims

Claims1. A non-rotating conveyor belt shaft adapted to support a rotating conveyor belt roller, the shaft including: a substantially elongate main body portion; and, an end portion provided at each end of said main body portion, wherein each end portion is configured to attach a respective end of said shaft to a support frame structure whilst also providing support to said conveyor belt roller via a bearing; wherein, said main body portion of said shaft is of a geometrical shape which is substantially non-circular in cross-section or of any other solid shape which is formed with at least one hole, perforation or cutout therethrough.

2. The shaft as claimed in claim 1 , wherein said shaft is configured to be of minimal weight and satisfy said predetermined structural design criteria, said criteria including any one or combination of: minimising deflection of said main body portion between the end portions of the shaft; minimising deflection of the shaft intermediate, between or beneath the bearings; maximising the second moment of area; maximising the area moment of inertia; maximising the second moment of inertia (MOI); minimising the cross-sectional area of the main body portion of the shaft; and, minimising the volume of material of the main body portion of the shaft.

3. The shaft as claimed in claim 1 or 2, wherein said main body portion of said shaft is designed to be of a geometrical shape which includes any one of: any solid shape which is substantially non-circular in cross-section; any hollow shape which is substantially non-circular in cross-section; a substantially rectangular shape; an I-beam shape; and / or,any solid shape which is formed with at least one hole, perforation or cutout at least partway therethrough.

4. The shaft as claimed in any one of the preceding claims, wherein at least said main body portion of said shaft is at least partly formed of: a metal material, such as steel or aluminium, or an alloy thereof; a non-metal material, such as a plastics material; a glass fibre reinforced plastics (GFRP) material.

5. The shaft as claimed in any one of the preceding claims, wherein said shaft is configured as a conveyor belt idler shaft.

6. A method of manufacturing a conveyor belt shaft as claimed in any one of the preceding claims, including the steps of: supplying a body of material; and, removing, by milling, shaving, grinding, or otherwise removing at least a portion of said body of material.

7. The method as claimed in claim 6, wherein in said removing step, said material is removed to form holes, orifices, slits, or cutouts from said body of material.

8. The method as claimed in claim 7, wherein said removing step is performed by a computer controlled machine.

9. The method as claimed in claim 8, wherein said removing step is performed according to an algorithm which calculates the minimum weight of the body whilst satisfying said predetermined design criteria.

10. The method as claimed in claim 9, wherein said predetermined design criteria includes any one or combination of: minimising deflection between the end portions of the shaft; minimising deflection of the shaft intermediate, between or beneath the bearings; maximising the second moment of area;maximising the area moment of inertia; maximising the second moment of inertia (MOI); minimising the cross-sectional area of the main body portion of the shaft; and, minimising the volume of material of the main body portion of the shaft.

11. The method as claimed in claim 10, wherein said shaft is an idler shaft of a conveyor belt roller.

Images