AU2004270321B2

AU2004270321B2 - Roller for a conveyor, particularly a belt or band conveyor

Info

Publication number: AU2004270321B2
Application number: AU2004270321A
Authority: AU
Inventors: Bernhard Hofmayer; Bernd Kuhfuss
Original assignee: Conv Australia Holding Pty Ltd
Current assignee: Conv Australia Holding Pty Ltd
Priority date: 2003-09-10
Filing date: 2004-09-07
Publication date: 2008-03-06
Anticipated expiration: 2024-09-07
Also published as: CA2538387C; PL1682437T3; AU2004270321A1; ES2300824T3; PT1682437E; EP1682437B1; CZ2006139A3; DE502004006348D1; DE10342099A1; CZ299905B6; EP1682437A1; CA2538387A1; WO2005023687A1; EP1682437B2; ATE387390T1

Abstract

The invention relates to a roller for a conveyor, particularly a belt or band conveyor, comprising a hollow cylindrical roll body (1) and an axle shaft (2), which is mounted in at least two bearings (4a, 4b), whereby the bearings (4a, 4b) are each placed in a bearing seat (3). The invention is characterized in that, in order to form the bearing seats (3), the wall of the roll body (1) is reshaped axially inward at both ends thereof whereby increasing the thickness of the wall in the area of the bearing seat (3).

Description

ROLLER FOR A CONVEYOR, PARTICULARLY A BELT OR BAND

CONVEYOR

The invention relates to a roller for a conveyor, in particular a belt or band conveyor, with a hollow-cylindrical roll body and an axle shaft mounted in at least two bearings, whereby the bearings are each arranged in a bearing seat.

A plurality of such rollers is placed parallel to one another in a frame. The conveyed goods run over these rollers. For conveying bulk goods, for example in mining, in each case 3 rollers are arranged in a V-shape relative to one another, so that the belt forms a trough. The length of such conveyors can be as much as several kilometres.

Due to the considerable weight of the conveyed goods the rollers must be designed to be stable. A bearing holder, in which one seat per roller bearings is formed, is set into the hollow-cylindrical roll body at its ends. The bearing holder is then welded to the inner wall of the roll body. Due to introduction of temperature during welding in of the bearing holder, the walls of the roll body and also the bearing seat buckle, so that both the roll body and the bearing seat must be reworked. So that sufficiently high forces can be transferred, the bearing holder must be designed to be very stable. The welding in of the bearing holder must be done very carefully, so that the roller can later run true. Due to the various operating steps involved, manufacturing such a roller is very time-consuming and thus costly. And due to the substantial forces to be transferred the roller must also be designed to be accordingly stable with considerable wall thickness, so that it is correspondingly heavy. When it comes to designing the conveyor, the weight of a roller is a not inconsiderable factor, in particular if the conveying distance is several kilometres.

Since the rollers must be set in rotation, the drive system must be designed accordingly heavy-duty.

Based on this problem the roller initially described should be improved. In particular, its manufacture should be simplified and its weight reduced also.

To solve this task a generic roller is characterised in that in the interests of designing the bearing seats the walls of the roll body are reshaped axially inwards at both ends.

Due to this configuration both bearing holders are omitted, whereby not only the weight is reduced, but also the manufacturing is lessened, since the procedural step of welding-in is omitted. The ends are reshaped inwards in such a way that an annular gap is formed between the cylindrical walls and the in-bent part of the walls, effectively increasing the stability of the bearing seat. This reshaping is executed by flow rollers, which is known for sealing off pipe ends pressure-tight, or forming necks. Tool and work piece are driven in rotation. Flow roller machines are available for example from the company GFU-Maschinenbau, Bitburg (www.gfuforming.com).

The wall thickness of the walls preferably increases in the region of the bearing seats, resulting in further weight optimising.

The external walls of the roll body can be made thin, as permitted by the requirements preset by the conveyor (transport load), whereas the walls in the vicinity of the bearing seats are thick enough for bearing forces to be safely transferred. In the region of the bearing seats the wall thickness in particular is preferably at least double. By way of comparison to conventional rollers this configuration saves up to 25 kg in weight, which, relative to the total number of rollers present in a long conveyor system, results in the drive unit being required to operate the conveyor having to make available much less power.

The bearing seats are worked by metal cutting after reshaping.

Commercially available roller bearings can then be pressed into the bearing seats.

The axial ends of the inwards-reshaped walls preferably run radially outwards and thus form a support ring.

Stability against bending is boosted by this configuration.

The axle shaft is preferably designed hollow for added weight optimising. If the axle shaft has at least one radial bore, simple air exchange between the interior of the roll body and the atmosphere is possible. The necessary air exchange is based on temperature differences arising from operating the conveyor. The roller is heated. The air enclosed inside the roll body expands. If the conveyor is stopped, the roller cools down and the enclosed air contracts. Through the bore into the roller axle the air exchange is not only possible quickly, but it is also ensured that the air does not flow through the roller bearings and carry along contaminants, which might curtail the shelf life of the bearings.

For easy mounting of the roller in the frame the ends of the axle shaft preferably have at least two diametrical flat surfaces (double-edged). The walls of the axle shaft run obliquely radially inwards between two flat surfaces preferably at least on one side.

In order to balance the rollers the hollow-cylindrical roll body is first overwound from outside to obtain a constant outer diameter, and then polyurethane foam is injected into the interior and the roller is set in rotation. Because of centrifugal forces the foam is applied on the inner wall over the full axial length. The layer thickness of the foam increases in the region of imbalance, or respectively decreases, thus equalising any imbalance. After a certain period the foam hardens and the roll body is permanently balanced with high precision. This process enables rapid and simple balancing, effectively further reducing the manufacturing time for the roller. Steel balls, as used for example for steel blasting, can be embedded in the synthetic layer, whereby even greater imbalances can be equalised.

By means of a diagram an embodiment of the invention will now be described in greater detail, in which: Figure 1 shows the lengthways section through a roller; Figure 2 shows the perspective view of a first axle shaft; Figure 3 shows the view of the axle shaft according to Figure 2; Figure 4a shows the front view of the axle shaft; Figure 4b shows the section along the line IV-IV according to Figure 3; Figure 5 shows the perspective view of a second axle shaft, Figure 6 shows the view of the axle shaft according to Figure 00 Figure 7a shows the front view of the axle shaft; F1Figure 7b shows the section along the line VII-VII according to Figure 6; CtFigure 8a shows the enlarged front view of the axle shaft; Figure 8b shows the detail VIII according to Figure 7b; t' Figure 9 shows a roller according to the prior art; Figure 10 shows the V-shaped arrangement of three rollers for forming a Strough.

SFigure 9 shows a conventional roller, as used for band or belt conveyor, used for transporting bulk goods, such as ore, gravel or the like. Such plants are several N kilometres long and have a plurality of parallel-spaced rollers. The belt width is for example 2300 mm. Three rollers are arranged in a V-shape (cf. Figure 10) to form a trough-shaped belt. The roller comprises the hollow-cylindrical roll body 1, the axle shaft 2 and two bearing holders 3a set on the ends of the roll body 1 and welded to the inner wall, in which a seat 3 for the roller bearings 4 is formed, which are in turn sealed off to the outside by a labyrinth seal The inventive roller comprises the hollow-cylindrical roll body 1, the hollow axle shaft 2 and the roller bearings 4a, 4b. Both ends of the roll body 1 are reshaped by flow rolling axially inwards and form the bearing seats 3. Reshaping of the ends takes place by a metal pipe forming the roll body 1 being drawn over an inner mandrel and heated inductively. The heated pipe is then set in rotation and a correspondingly profiled forming tool runs rotatingly into the pipe end and crimps the walls inwards. The material of the walls flows in a radial direction during reshaping, so that the wall thickness of the reverse drawing 7 is essentially greater than the wall thickness of the remaining pipe. Through corresponding profiling of the forming tool the ends of the reverse drawing 7 migrate radially outwards during reshaping and form a support ring 6, effectively increasing stability against bending of the roll body 1 or respectively the bearing seats 3. After reshaping the bearing seats 3, which take up the roller bearings 4a, 4b, are milled in the reverse drawing 7.

The axle shaft 2 is designed hollow and its middle region is designed larger in diameter than the ends, which are mounted in the roller bearings 4a, 4b. Arranged in the larger diameter region of the axle shaft 2 is a radial bore 8, via which air exchange can take place between the interior 10 of the roller and the atmosphere.

After the bearing seats 3 have been milled, the roll body 1 is overwound outside and then the roll body 1 is balanced.

For this, a synthetic foam 9 is injected into the rotating roll body 1, which, as a result of centrifugal forces on the innerwall is applied overthe full axial length and hardens after a certain period, whereby the thickness of the polyurethane layer 9 forms variously, according to imbalance. In the polyurethane foam metal balls with a diameter of 1.5 mm, and not illustrated in greater detail here, can be mixed. Such balls are used for example for steel blasting.

The ends of the axle shaft 2 exhibit two diametrical flat surfaces 11, so that the roller can be set torsion-free into a frame, not illustrated in greater detail here. As Figures 5 to 8b show, the ends of the axle shaft 2 can have on one side between the flat surfaces 11 a radial bevel 12, and form a "trihedron" with the flat surfaces 11.

It is evident that the wall thickness of the axle shaft 2 in the middle region is thinner than at the ends, in which the force is introduced via the roller bearings 4a, 4b. The varying wall thickness is achieved by a pipe with a continuous cylindrical outer diameter and a wall thickness constant over the length first being set on a mandrel, and in the region, which is later the middle region of the axle shaft 2, the wall thickness is reduced by a kneading tool being advanced onto the pipe from outside. The inner diameter of the pipe remains constant, the middle region with the reduced wall thickness has a smaller outer diameter than the pipe ends with greater wall thickness. A tool, which forms the material radially inwards, is then fed rotatingly against the pipe ends from outside until the ends exhibit the same outer diameter as the middle region.

Legend 1 roll body 1' inner wall 2 axle shaft 3 bearing seat 3a bearing holder 4a roller bearings 4b roller bearings labyrinth seal 6 support ring 7 reverse drawing 8 bore 9 synthetic layer/polyurethane layer/foam interior 11 flat surface 12 radial bevelling

Claims

1. A roller for a conveyor, in particular belt conveyor, having a hollow-cylindrical roller t' body and an axial shaft mounted in at least two bearings (4a, 4b), the bearings (4a, 4b) being arranged in a bearing seat characterized in that, for the purpose of forming the bearing seats the walls of the roller body is formed axially inwards at its two ends by flow rolling, the wall thickness of the wall increasing in the region of the bearing seats

2. A roller according to Claim 1, characterized in that the wall thickness of the wall at least doubles in the region of the bearing seats

3. A roller according to either of Claims 1 and 2, characterized in that the bearing seats are machined.

4. A roller according to Claim 1, characterized in that the axial ends of the inwardly formed wall diverge radially outwards and form a support ring A roller according to any one or more of the preceding claims, characterized in that the axial shaft is of hollow design.

6. A roller according to Claim 5, characterized in that the axial shaft has at least one radial bore

7. A roller according to any one or more of the preceding Claims, characterized in that the ends of the axial shaft have at least two diametrically arranged flattened portions (11).

8. A roller according to Claim 7, characterized in that the wall of the axial shaft runs radially inwards in an oblique manner on at least on one side between two flattened portions (11).

9. A roller according to Claim 1, characterized in that a plastic layer is provided on the inner wall of the roller body (1)and extends over the entire axial length. 00 8 C1 10. A roller according to Claim 9, characterized in that steel balls are embedded in the Splastic layer