WO2010026533A2

WO2010026533A2 - Conveyor idler

Info

Publication number: WO2010026533A2
Application number: PCT/IB2009/053826
Authority: WO
Inventors: Robert Eichhorn; Bogdan Bogdanovic
Original assignee: Robert Eichhorn; Bogdan Bogdanovic
Priority date: 2008-09-02
Filing date: 2009-09-02
Publication date: 2010-03-11
Also published as: WO2010026533A3

Abstract

This invention relates to a roller and more particularly, but not exclusively to a conveyor idler roller. The invention also relates to a method of manufacturing a conveyor idler roller, and more particularly, but not exclusively, to a method of manufacturing a nylon or engineering plastic conveyor idler. The method includes the steps of providing at least two cylindrical shell elements made of a synthetic material, the shell elements having complementary profiled ends in order for the ends to mate when the shell elements are located end-to-end adjacent one another; and securing the cylindrical elements to one another by way of a friction welding process in order to form a composite shell.

Description

CONVEYOR IDLER

FIELD OF THE INVENTION

This invention relates to a roller and more particularly, but not exclusively to a conveyor idler roller. The invention also relates to a method of manufacturing a conveyor idler roller, and more particularly, but not exclusively, to a method of manufacturing a nylon or engineering plastic conveyor idler.

BACKGROUND TO THE INVENTION

Conveyor systems, and thus conveyor idlers, are ubiquitous in various industries where materials handling and transport by way of conveyor systems are required. Many different types of conveyor idlers are known, but conveyor idlers are still continuously improved in order to reduce cost, increase reliability, and reduce the effect that conveyor idlers have on conveyor belts carried thereby.

Conveyor idlers made of synthetic materials are becoming increasingly prevalent. However, the challenge is to design and produce a roller that can compete with the predominantly metallic market in terms of providing better wear characteristics, weight savings, comparable load carrying capacity and improved operational statistics such as breakaway mass (the torque required to produce rotation from standing still) and running friction (the torque required to keep a roller rotating at a constant speed) at an economic price.

A number of problems remain to be solved with these types of conveyor idlers, including: β Improved design and material choice - Traditional materials used in the manufacture of synthetic conveyor rollers have limitations in terms of load carrying capacity, i.e. absolute tensile strength and tubular rigidity/resistance to deflection under load. As a roller gets longer and/or is exposed to large loads the roller tube deflects/bends and causes deflection at the bearing leading to premature failure of the roller;

• Lengths and load carrying capacity limitations of traditional synthetic rollers due to materials not being sufficiently rigid;

® Warping of rollers over time due to unstable design material, whether under load or not; © Increasing of material volume to provide the required rigidity, which then negatively affects the performance, weight and economic benefits of using synthetic materials;

• Economical manufacturing of diverse roller sizes and load carrying capabilities that users require; and β Establishing suitable methods of manufacture that ensure dimensional accuracy after moulding, as well as the provision of adequate cooling measures to protect the plastic material during operation, which may be somewhat heat sensitive, in that the plastic may serve as a heat sink.

It is accordingly an object of the invention to provide a method of manufacturing a conveyor idler, as well as a conveyor idler manufactured by such method, which will at least partially alleviate the abovementioned disadvantages, and/or which will also be a useful alternative to existing conveyor idlers and methods of manufacturing the same.

SUMMARY OF THE INVENTION

According to the invention there is provided a method of manufacturing a conveyor idler, the method including the steps of: providing at least two cylindrical shell elements made of a synthetic material, the shell elements having complementary profiled ends in order for the ends to mate when the shell elements are located end-to-end adjacent one another; and securing the cylindrical elements to one another by way of a friction welding process in order to form a composite shell.

There is provided for a plurality of cylindrical shell elements to be secured end to end to obtain a composite shell of a required length.

Preferably, at least one end of a shell element terminates in a flange section, which is in use secured to a complementary flange formation of an adjacent shell element.

The flanges sections of adjacent shell elements are complementary profiled.

There is provided for the flange sections to extend radially inwardly from an outer wall of the shell element, and for at least a part of the flange formation to have a non-linear profile.

Preferably, each flange formation includes an outer zone and an inner zone.

The outer zone may have a non-linear profile, and preferably may be at least partially castellated or crenulated due to the presence of alternating annular groove and ridges, with an outer flange zone of one of the shell elements being inversely configured to an outer flange zone of an adjacent shell element.

The inner zone of the flange formation may be in the form of a planar annular disc extending inwardly from the outer zone.

The method may also include the steps of: providing a bearing housing made of a synthetic material; and securing the bearing housing to an operatively outer end of a shell element by way of a friction welding process.

Bearing housings may be secured to opposing ends of the composite shell.

There is provided for a spigot formation to extend from the bearing housing, and for a complementary socket formation to be defined by the cylindrical shell of the shell element, wherein the friction weld is formed between an outer wall of the spigot formation and an inner wall of the shell.

The spigot formation is configured and dimensioned snugly to fit inside the socket formation. Preferably, the spigot formation forms an interference fit within the socket formation.

Each bearing housing may include a plurality of fins for in use providing movement of air around the bearing housing so as to cause cooling of the bearing housing.

Preferably, each bearing housing comprises an inner tubular core and an outer sleeve that forms an annulus therebetween, wherein the fins extend radially between the core and the outer sleeve.

There is further provided for the method to include the steps of: securing a plurality of shell elements to one another by way of a friction welding process so as to form a composite shell; and securing bearing housings to distal ends of the composite shell by way of a friction welding process.

Preferably the shell and bearing housings are made from Nylon or any other suitable engineering plastic that when combined with other additives may solve the challenge of making the roller conductive and flame retarded without significantly reducing the mechanical properties of the base material.

There is also provided for the shell and bearing housing to be made of a glass fibre reinforced synthetic material.

There is also provided for the shell and bearing housings to be injection moulded.

According to a further aspect of the invention there is provided a conveyor idler including: at least two cylindrical shell elements made of a synthetic material, the shell elements having adjacent ends that include complementary profiled, radially inwardly protruding flanges that are secured to one another.

There is provided for the conveyor idler to include a plurality of cylindrical shell elements secured end to end so as to form a composite shell.

There is still further provided for bearing housings to be secured to distal ends of the composite shell.

At least one flow passage is provided through the bearing housing so as to allow airflow from the shell when a bearing is located inside the bearing housing.

Preferably, the flow passage is in the form of a longitudinal groove provided in an inner wall of the tubular core.

There is still further provided for radially inwardly protruding fins to extend from the inner surface of the shell. The fins may be similar to that described in the applicants South African patent no 2006/07093, the contents of which is incorporated herein by reference.

There is also provided for the width of the fins to decrease from the inner end of a shell element to an outer end of a shell element. BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described by way of non-limiting examples, and with reference to the accompanying figures in which:

Figure 1 is a partially exploded perspective view of a conveyor idler in accordance with a first embodiment of the invention;

Figure 2 is an assembled perspective view of the conveyor idler of figure 1 ; and

Figure 3 is a cross-sectional side view of one halve of the conveyor idler of figure 1;

Figure 4 is a cross-sectional side view of a second embodiment of a shell of the conveyor idler; and

. Figure 5 is a cross-sectional side view of a bearing housing for use with the shell of Figure 3 or Figure 4.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, in which like numerals indicate like features, a non- limiting example of a conveyor idler in accordance with the invention is generally indicated by reference numeral 10. The conveyor idler includes a cylindrical shell 20, with two bearing housings 30 secured to opposing ends of the shell 20. The bearing housings 30, as well as the shell 20, are made of a synthetic material, and more particularly is made of Nylon which may be reinforced with glass fibre.

The shell 20 is circular and cylindrical, and includes an outer surface 21 , which in use defines a bearing surface of the conveyor idler 10, and an inner surface 22. Radially inwardly extending fins 23 extends from the inner surface 22 into an inner cavity of the shell 20. The purpose of these fins 23 is, inter alia, to provide structural strength to the shell 20, to prevent the shell from warping during the process of moulding during the manufacture thereof, and also to provide air movement inside the shell, hence assisting with internal cooling of the shell 20. The air within the shell is allowed to move outward and past a centrifugal seal. This seal, unlike other seals, is not a barrier seal, and due to its design uses centrifugal forces to expel foreign particles. The circulation within the shell may be aided by the centrifugal seal drawing the air from within and expelling it out. The displacement of air form the shell is furthermore aided by the introduction of flow passages 31.2 in the bearing housing 30, as is described in more detail below. As can be seen in figure 4, in one embodiment the internal fins 23 reduces in height from the inner end 24 to the outer end 25, due to the maximum bending moment being induced towards the centre of the shell 20, and a smaller bending moment being present at the ends.

The shell 20 is furthermore of a composite or modular arrangement, and comprises at least two cylindrical elements 20.1 , each having an inner end 24 and an outer end 25. The inner ends 24 of adjacent shell elements are secured to one another by way of a friction welding process. These elements may be combined with further intermediate cylindrical elements (not shown) by friction welding to produce alternative dimensions to suit other conveyor belt widths. Also, two shell elements 20.1 of different lengths may be secured to one another so as to form a shell having a different length to what would have been the case had two shell elements of the same lengths been secured to one another.

Referring now specifically to Figure 4, a flange formation 24.1 extends radially inwardly from the inner end 24 of each shell element 20.1. The flange formation 24.1 includes an outer zone 24.2 that extends from the wall of the shell 20, and an inner zone 24.3 that extends radially inwardly from the outer zone 24.2. The outer zone 24.2 has a non-linear cross-sectional profile, and more particularly in this embodiment is at least partially castellated or crenulated due to the presence of alternating annular groove and ridges. The outer flange zone 24.2 of one of the shell elements 20.1 is inversely configured to an outer flange zone of an adjacent shell element 20.1. The inner zone 24.3 of the flange formation is in the form of an annular disc extending inwardly from the outer zone 24.2. The mating non-linear outer flange zones 24.2 of adjacent shell elements 20.1 ensures proper alignment for the purposes of friction welding, whilst also resulting in a larger welded area due to the increased contact surface. Likewise, it is foreseen that the inwardly extending flange will further increase the welded area, and therefore the effective length of the weld, therefore further improving the integrity of the weld formed by friction welding. It should however be noted that the inner flange zone 24.3 may in certain cases be omitted. Alternatively, the non-linear part of the flange formation may be omitted, as is shown in Figure 3.

Two bearing housings 30, best seen in Figures 3 and 5, are secured to the shell 20 at the outer ends 25 thereof. Each bearing housing 30 includes a tubular core 31 , defining a bearing seat 31.1 suitable for receiving a bearing, and an outer cylindrical sleeve 32. An annular space is formed between the tubular core 31 and the outer sleeve 32. Fin formations 33 extend in a radial direction between the tubular core 31 and the outer sleeve 32, and in use displaces air away from the tubular core 31, and thus the bearing (not shown), thus effectively assisting in cooling of the bearing housing. In addition, it is also foreseen that the fins 33 may cause at least some air movement behind a centrifugal seal (not shown) of the conveyor idler, thus at least partially preventing ingress of dust in to the seal and bearings and contributing to the centrifugal expulsion of unwanted particles from the inside of the bearing housing. Flow passages 31.2 are provided in the bearing housing 30, and more particularly are in the form of at least one longitudinal groove formed in the inner wall of the tubular core 31. When the bearing (not shown) is located in the bearing housing 30, the flow of air through the bearing housing is facilitated by the flow passages 31.2 that effectively bypass the bearing. This ensures that air inside the shell is expelled from the shell due to the motion imparted by the internal fins 23 when the idler starts rotating,

The bearing housings 30 also include spigot formations 34 extending therefrom (shown in Figure 3), the spigot formations being configured and dimensioned to fit inside a socket formation defined by outer ends 25 of the shell 20. The fit is designed to be an interference fit, and the spigot formations 34, and hence the bearing housings 30, are secured to the shell 20 by way of a friction welding process. The weld formed is relatively long, due to the spigot extending into the socket formation, as opposed to a bearing housing that merely abuts an end of a shell.

During the manufacturing process of the conveyor idler 10, the shell elements 20.1 of the shell 20, as well as the two bearing housings 30, will all be manufactured separately by way of a moulding process, and in particular by way of an injection moulding process. Once the components have been manufactured the shell elements 20.1 will be secured to one another so as to form a composite shell 20 having a required length. The shell elements 20.1 are secured to one another by way of a friction welding process so as to form a secure weld therebetween. Thereafter, the bearing housings 30 will also be secured to ends of the composite shell 20 by way of a friction welding process, so as to form secure welds between the outer ends 25 of the shell 20 and the spigot formations 34 of the bearing housings 30. The utilisation of composite shell, and in particular a composite shell manufactured using a friction weld method simplifies the manufacturing process, and - significantly - also enables the application of a modular design methodology as described below.

In one embodiment a conveyor idler manufactured using the above method may include two shell elements of the same lengths and two bearing housings. However, it will be appreciated that shell elements of different lengths may be secured to one another to obtain a composite shell of a different length. Further intermediate shell elements may even be provided in order to manufacture a composite shell having any required length. This modular arrangement is both innovative and economic, and results in a substantial reduction in capital cost, as the same standard shell elements can be used to manufacture a whole range of conveyor idlers. In order fully to accommodate the possible length permutations required in typical conveyor design, it is more economical to design parts and different moulds that, when combined, result in the required length of roller rather than constructing the moulds for every typical permutation. For example, if one assumes a constant length for the bearing housing on either side of the shell of 1.4" (35mm), the combination of one half of an 18" shell (457mm) with one half of the 13" shell will yield a 15 Yz" (400mm) shell. By making two moulds three conveyor belt widths can be served at a reduced cost.

It will be appreciated that many modifications or variations of the invention are possible without departing from the spirit or scope of the invention.

Claims

CLAIMS:

1. A method of manufacturing a conveyor idler, the method including the steps of: providing at least two cylindrical shell elements made of a synthetic material, the shell elements having complementary profiled ends in order for the ends to mate when the shell elements are located in an end-to-end relationship adjacent one another; and securing the cylindrical shell elements to one another by way of a friction welding process so as to form a composite shell.

2. The method of claim 1 wherein at least one end of a shell element terminates in a flange formation, which is in use secured to a complementary flange formation of an adjacent shell element by way of the friction welding process.

3. The method of claim 2 wherein the flange formation extend radially inwardly from an outer wall of the shell element

4. The method of claim 3 or claim 4 wherein at least a part of the flange formation has a non-linear profile.

5. The method of any one of claim 2 to 4 wherein the flange formation includes a radially outer zone and a radially inner zone, the radially outer zone having a non-linear profile, and the radially inner zone being substantially planar.

6. The method of claim 5 wherein the radially outer zone is at least partially castellated or crenulated due to the presence of alternating annular groove and ridges, with an outer flange zone of one of the shell elements being inversely configured to an outer flange zone of an adjacent shell element.

7. The method of claim 5 wherein the radially inner zone is in the form of a planar annular disc extending inwardly from the outer zone.

8. The method of any one of the preceding claims further including the steps of: providing a bearing housing made of a synthetic material; and securing the bearing housing to an operatively outer end of a shell element by way of a friction welding process.

9. The method of claim 8 wherein bearing housings are secured to opposing ends of the composite shell.

10. The method of claim 8 or claim 9 wherein a spigot formation extends from the or each bearing housing, and wherein a complementary socket formation is defined by the cylindrical shell of the shell element, in order for a friction weld to be formed between an outer wall of the spigot formation and an inner wall of the shell during the step of securing the bearing housing to the shell element.

11. The method of any one of the preceding claims including the steps of: securing a plurality of shell elements to one another by way of a friction welding process so as to form a composite shell; and securing bearing housings to distal ends of the composite shell by way of a friction welding process.

12. The method of any one of the preceding claims in which the shell elements and bearing housings are injection moulded.

13. A conveyor idler including a composite shell that comprises at least two cylindrical shell elements made of a synthetic material, wherein the shell elements are secured to one another in an end-to-end configuration.

14. The conveyor idler of claim 13 in which the shell elements have adjacent ends that include complementary profiled and radially inwardly protruding flanges that are secured to one another so as to form the composite shell.

15. The conveyor idler of claim 13 or claim 14 wherein bearing housings are secured to distal ends of the composite shell.

16. The conveyor idler of claim 15 wherein each bearing housing includes a plurality of fins for, in use, providing movement of air around the bearing housing so as to cause cooling of the bearing housing.

17. The conveyor idler of claim 16 wherein each bearing housing includes an inner tubular core and an outer sleeve that forms an annulus therebetween, wherein the fins extend radially between the core and the outer sleeve.

18. The conveyor idler of claim 17 wherein at least one flow passage is provided through the bearing housing so as to allow airflow from the shell when a bearing is located inside the bearing housing.

19. The conveyor idler of claim 18 wherein the flow passage is in the form of a longitudinal groove provided in an inner wall of the tubular core.

20. The conveyor idler of claim 15 wherein a spigot formation extends from the bearing housing, the spigot formation engaging a socket formation defined by the cylindrical shell of the shell element.

21. The conveyor idler of any one of claims 13 to 20 including longitudinal fins protruding radially inwardly from an inner surface of each shell element.

22. The conveyor idler of claim 21 wherein the height of the fins decrease from an operatively inner end of a shell element to an operatively outer end of a shell element.

23. The conveyor idler of any one of claim 13 to 22 wherein the shell elements are secured to one another, and also to the bearing housings, by way of friction welding.

24. A kit for constructing a conveyor idler including at least two shell elements and two bearing housings made of a synthetic material.