WO1997011293A1

WO1997011293A1 - An improvement in wheels, such as e.g. chain wheels, pulleys and the like

Info

Publication number: WO1997011293A1
Application number: PCT/SE1996/000524
Authority: WO
Inventors: Niclas Johansson
Original assignee: FB KEDJOR AB
Current assignee: FB KEDJOR AB
Priority date: 1995-09-21
Filing date: 1996-04-24
Publication date: 1997-03-27
Anticipated expiration: 1998-03-21
Also published as: SE9503276L; SE9503276D0; SE507163C2; AU6019096A

Abstract

A wheel having a central hub and a central bore for mounting of the wheel on a shaft, comprises two or more individual, separately manufactured and essentially circular discs which are axially clamped together to form the wheel disc of the wheel. One or more of the individual discs comprises a material, different from that of the remaining discs, and the individual discs are divided in a diametrical division plane that intersects the rotary axis of the discs. A hub, preferably situated on one side of the wheel disc, similarly comprises individual discs which are axially clamped together and clamped to the remainder of the wheel disc. In a wheel having a key slot opening towards the shaft bore, the divisional plane of one or more of the individual discs is preferably angularly off-set in relation to the divisional plane of one or more of adjacent discs so that the individual discs may be mounted on a shaft in different angular positions whereas their respective key slots assume one and the same angular positions. The individual discs or disc portions, respectively, are individually cut by means of a computer controlled laser cutting device. The wheel may also be designed to constitute a V-belt pulley.

Description

An improvement in wheels, such as e.g. chain wheels, pulleys and the like

The present invention relates to an improved wheel, adapted to be mounted on a shaft, preferably a rotary jour¬ nalled shaft.

One embodiment of the invention is concerned with con¬ veyor chain wheels, particularly conveyor chain wheels of the kind which is adapted to engage with a chain, such as a con¬ veyor chain, in order to support, guide and possibly also drive the same. In this instance the invention is particularly concerned with a conveyor chain wheel having an essentially circular wheel disc, which has circumferentially spaced teeth for engagement with a conveyor chain and a central bore for monting of the wheel on a shaft and which preferably, at least on one side, is provided with a hub, similarly with a bore for mounting on the shaft.

Another embodiment of the wheel according to the inven¬ tion has the shape of a V-belt pulley comprising a central hub and a surrounding wheel rim having one or more V-belt grooves for V-belts.

The object of the present invention has been to provide a wheel, being either a conveyor chain wheel or the like or a V- belt pulley, that exhibits advantages both with respect to the manufacture and the operation and with respect to environmen¬ tal requirements as compared to prior art wheels of this cate¬ gory. A further object of the invention has been to provide a wheel which is easier to mount at the initial installation than prior art wheels of the category in question and which, furthermore, is easier to remove and replace than the prior art wheels of the category in question.

A still further object of the invention, particularly in connection with its application to V-belt pulleys which nor¬ mally operate at comparatively high speeds, such as of the order of 750 r.p.m. or higher, viz. up to about 3000 r.p.m., has been to provide a V-belt pulley which is very homogenous with respect to the material structure, so that the pulley may operate very balanced and also, if required, may be adjusted with respect to the balance, e.g. by removing certain portions or by the addition of balancing elements.

The first mentioned object is achieved by the wheel ac¬ cording to the invention which is characterized essentially in that the wheel comprises two or more individual, separately manufactured and essentially circular disc portions, which are axially clamped together to form the wheel disc of the wheel.

Preferably, one or more of the individual discs is made from a diffferent material than that of the other discs.

The seond one of the above mentioned objects of the in¬ vention is achieved in that the individual discs are divided along a diametric division plane which intersects the rotatio¬ nal axis of the discs.

In case the wheel is provided with at least one hub on one side of the wheel disc it is preferred that also the hub comprises individual disc portions which are axially clamped together with each other and with the remainder of the wheel disc.

If the wheel is provided with a key slot which is open towards the shaft bore of the wheel it is preferred that the divisional plane of one or more of the individual discs is angularly off-set in relation to the divisional plane of one or more of the adjacent discs, so that the individual discs may be mounted on a shaft in different angular positions whe¬ reas their respective key slots assume one and the same an¬ gular positions.

In order to realize the desire of an easy and inexpensive as well as easily adaptable manufacture of the chain wheel according to the invention it is preferred that the individual discs or disc portions, respectively, are individually cut by means of a computer controlled laser cutting device.

It may advantageously be conceived to make the wheel according to the invention in the shape of a V-belt pulley having a central hub, somprising hub disc portions, and an outermost wheel rim, comprisin rim portions, which rim portion is connected to the hub by means of two or more spokes, pre¬ ferably formed in centrally located metal sheets only, whe¬ rein, if necessary, both the hub disc portions, the wheel rim portions and the spokes are axially clamped together .

In case the wheel has the shape of a V-belt disc then the thickness of the sheet metal is preferably chosen so, that each V-belt contacts only one metal sheet on each side in order to avoid wearing junctures on each side.

The invention will be disclosed in more details below with reference to the accompanying drawing which illustrates one embodiment of a conveyor chain wheel according to the the invention, picked as an example, and one embodiment of a V- belt pulley according to the invention, similarly picked as an example.

Figure 1 shows the chain wheel in an end view and figure 2 shows the chain wheel in a diametric section, parallel to the central axis of the wheel; figure 3 shows a V-belt pulley in an end view and figure 4 shows the Velt pulley in figure 3 as seen in a diametric section parallel to the central axis of the V-belt.

The chain wheel shown as an example in fig. 1 and 2 comp¬ rises an essentially circular wheel disc 10, which around the periphery thereof has nine teeth 11 that are designed in a suitable manner for engagement with a chain, not shown, such as a conveyor chain. In the example the chain wheel 10 compri¬ ses four essentially circular discs 10A, 10B, IOC and 10D, but it could, in practise, comprise more or fewer discs than four. The numberof discs 12A, 12B etc is determined from case to case in dependence of the demands in each case.

In the example there is disposed, on one side of the wheel disc, generally denoted 10, a hub, generally denoted 12, which comprises a number of essentially circular discs 12A, 12B etc. The number of discs 12A, 12B of the hub is determined from case to case in accordance with the demands in each case.

In as much as the chain wheel according to the invention comprises a plurality of individual discs the possibility is offered to manufacture such discs, e.g. the outermost ones, which may be subjected to a severe wear or a tough mechanical influence by blows or strokes, from a hard and resistant mate¬ rial, whereas such discs, that are not apt to be subjected to wear or a tough mechanical influence, may be manufactured from a softer material, such as e.g. certain plastics. Of course, the same considerations apply to the individual discs 12A, 12B etc of the hub 12.

The discs 10A, 10B, IOC are connected to each other by means of a plurality of screws 13 (eight in the example) which extend parallel to the rotational axis C of the chain wheel, in the example in the shape of screws having countersunk heads with internal hexagonal recesses 14, which screws extend through all of the discs 10A, 10B, IOC, and 10 D.

In a corresponding manner the discs 12A, 12B etc. which jointly form the hub, generally denoted 12, are connected to each other by means of a number of screws 15 (in the example four in number) which extend parallel to the rotational axis C of the chain wheel, in the example in the shape of screws having countersunk heads with internal hexagonal recesses 16, which screws extend through all discs 12A, 12B etc of the hub.

Both the wheel disch, generally denoted 10, and the hub, generally denoted 12 have a central bore 17 to receive a shaft, and an axial key slot 18 which opens towards the shaft bore and is adapted to receive an ordinary key, not shown.

According to the invention the discs 10A, 10B, 10C and 10D are divided into two essentially circle sector shaped portions 10A' ch 10A", respectively, wherein the line DL of division between the two portions extends diametrically over the respective disc and extends through the centre of the disc. In this way it has been made possible to mount the chain wheels on a shaft simply by mounting the sector shaped parts, which jointly form the discs, on the shaft from the side and only then to join the disc portions into a package by means of the axially extending screws 13 and 15.

Preferably the line of division DL of at least some of the individual discs is angularly off-set e.g. a quarter of a full turn in relation to the line of division of the other discs, which results in a possibility to mount the discs 10A- 10D in such a manner that an "uninterrupted" portion of one disc will cover and bridge the line of division of adjacent discs.

In the example both the individual discs 10A-10D and the hub discs 12A, 12B are each provided with two axially exten¬ ding bores 19, into which guide pins, not shown, may be in¬ serted. Such bores 19 and the corresponding pins may be manu¬ factured with much closer tolerances than the shaft bore 17 and the key slot 17 as well as the bores for the screws 13, 15, and thus they afford an increased precision to the chain wheel as a hole, so that the teeth will be situated exactly in flush with each other.

The V-belt pulley 30 shown as an example in figs 3 and 4 is built up in principally the same way as the chain wheel in fig. 1 and 2 and comprises three individual, central sheet metal discs 21, 22, 23, and likewise individual, radially innermost and outermost rim discs 24, 25 which are clamped together by means of axially acting clamping screws 25, 27, 28 in the corresponding way as has been described above with respect to the chain wheel 10.

The outer peripheries of the rim discs 25 are designed to form V-bel grooves and the thickness of these rim discs is preferably such that the V-belts will rest only on the sides of the grooves in question.

The central plates 21, 22, 23, need not be disc shaped but may be designed to form two or more spokes.

To be complete it should be mentioned that all the above considerations with respect to V-belt grooves, planes of divi¬ sion, the mutual angular off-set of the planes of division, y, guiding pins etc. are applicable also to V-bel pulleys of the kind as generally shown in figs. 3 and 4.

A plurality of modifications and alterations as to de¬ tails may be made within the scope of the inventive idea.

Claims

C L A I M S

1. An improvement in wheels, adapted to be mounted on a shaft, preferably a rotary journalled shaft, such as chain wheels and the like, particularly conveyor chain wheels having an essentially circular wheel disc, which has circumferential¬ ly spaced teeth for engagement with a conveyor chain and a central bore for monting of the wheel on a shaft character zed in that the wheel comprises two or more individual, separately manufactured and essentially circular disc portions, which are axially clamped together to form the wheel disc of the wheel.

2. A wheel as claimed in claim 1, characterized in that one or more of the individual discs consists of a material diffe¬ rent from that of the other discs.

3. A wheel as claimed in claim 1 or 2, characterized in that the individual discs are divided along a diametric division plane which intersects the rotational axis of the discs.

4. A wheel as claimed in one of claims 1 - 3 having a hub on at least one side of the wheel disc, characterized in that also the hub comprises individual disc portions which are axially clamped together with each other and with the remain¬ der of the wheel disc.

5. A wheel as claimed in one or more of claims 1 - 4 having a key slot opening towards the shaft bore of the wheel, charac¬ terized in that the divisional plane of one or more of the in¬ dividual discs is angularly off-set in relation to the divi¬ sional plane of one or more of the adjacent discs, so that the individual discs may be mounted on a shaft in different an¬ gular positions whereas their respective key slots assume one and the same angular positions.

6. A wheel as claimed in one or more of claims 1 - 5, charac¬ terized in that the individual discs or disc portions, respec¬ tively, are individually cut by means of a computer controlled laser cutting device.

7. A wheel as claimed in one or more of claims 1 - 6, charac¬ terized in that the wheel is designed to form a V-belt pulley.

8. A wheel as claimed in claim 7, characterized in that the wheel comprises a few central, supporting individual discs and a plurality of individual discs which form a hub and a radial¬ ly outermost disc rim with V-belt grooves, respectively.

9. A wheel as claimed in claim 7 or claim 8, characterized in that the central, supporting discs are designed as spokes between the hub and the outermost disc rim having V-belt groo¬ ves.

10. A wheel as claimed in any of claims 7 - 9, characterized in that the thickness of the individual sheets is chosen so, that the V-belts will be resting only against the sides of the V-belt grooves.