GB2334274A

GB2334274A - A guide unit for a mining machine mounted on a scraper chain conveyor

Info

Publication number: GB2334274A
Application number: GB9901877A
Authority: GB
Inventors: Gert Braun
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-02-12
Filing date: 1999-01-29
Publication date: 1999-08-18
Anticipated expiration: 2019-01-29
Also published as: DE19805666A1; GB2334274B; GB9901877D0; PL190518B1; PL331034A1

Abstract

A guide unit for a cutting machine 2 is described, which comprises a specially constructed guide rail 3 and a round link chain 5, wherein a driven chain star wheel 8 of the cutting machine 2 engages in the horizontal links 6 of the round link chain 5. The vertical links 7 of this round link chain are constructed as short rolling links 7, so that when the teeth of the chain star wheel 8 are in engagement these vertical links 7 can travel with rolling contact, with the avoidance of sliding friction. The very large vertical clearance for the horizontal links 6, along with the rolling links 7 of the special round link chain 5, within the guide rail 3 enables the optimum kinematics of the feed system to be achieved and reduces the required driving forces or driving energy.

Description

"A guide unit for a mining machine, particularly a cutting machine, disposed on a scraper chain conveyor" This invention relates to a guide unit for a mining machine, particularly a cutting machine, disposed on a scraper chain conveyor, comprising a guide rail with an engagement channel and comprising a round link chain which is mounted in the guide rail and which has horizontal links and which has vertical links constructed as short links, wherein the horizontal links are disposed in the guide rail with a predetermined motional clearance and a driven chain star wheel of the cutting machine engages in the horizontal links and in the engagement channel. When the guide rail is completely contaminated by material being conveyed, this engagement generally occurs with the horizontal links of the round link chain floating on the material being conveyed, as it were.

A guide unit of this type is known for cutting machines which are guided on scraper chain conveyors in which the round link chain has horizontal links and vertical links of identical construction. In another known form of construction, the vertical links are constructed as short links and are consequently shorter t an the horizontal links, in order to achieve a closer engagement for the chain star wheel of the cutting machine. In both cases it is unsatisfactory that when the teeth of the chain star wheel engage in the horizontal links, sliding friction has to be accepted as a consequence of the resulting relative movements between the tooth flanks of the chain star wheel and the vertical links. Sliding friction of this type results in considerable wear, and moreover the degree of contamination of the guide rail constantly changes the kinematics of the engagement of the teeth. Furthermore, taking into account the fact that hardly any vertical motional clearance exists, the vertical links have no path of rotation away from the teeth of the rotating chain star wheel which engage in the horizontal links between the vertical links, and after a certain pressure point is exceeded they jump off the teeth. This results in the round link chain being stressed jerkily and in increased wear phenomena with an increased risk of damage and breakage, particularly when there is an increase in driving energy. The aim of the invention is to provide a remedy here.

A basic object of the present invention is to create a guide unit of the form of construction described at the outset for a mining machine, particularly cutting a machine, which is disposed on a scraper chain conveyor, which guide unit is distinguished, even when the guide rail is subject to a relatively large extent of contamination, by a construction and mode of displacement of the round link chain which result in a simple manner in reduced wear and in an increased level of operational reliability, and which reduce the requisite driving energy.

According to the present invention, there is provided a guide unit for a mining machine, particularly a cutting machine, disposed on a scraper chain conveyor, comprising a guide rail with an engagement channel and comprising a round link chain which is mounted in the guide rail and which has horizontal links and which has vertical links constructed as short links, wherein the horizontal links are disposed in the guide rail with a predetermined motional clearance and a driven chain star wheel of the cutting machine engages in the horizontal links and in the engagement channel, with the vertical links constructed as rolling links with a circular inside diameter and a circular outside diameter, and with the horizontal links mounted in the guide rail with an oversize vertical motional clearance The result of these measures according to the invention is that the teeth of the driven chain star wheel which engage between the vertical or rolling links exert a torque such that the rolling links rotate taking into account the linear contact between the rolling links and the engaging horizontal links and can slide along the inner curvature of the horizontal links as it were, whilst the tooth flanks of the chain star wheel form part of a system of motion comprising travel with rolling contact and comply with the kinematics in the optimum manner. In this respect, a rolling motion is executed with the form of construction according to the invention, the rolling resistance of which, and consequently the rolling friction of which, are very much less than the sliding friction of the teeth in conventional forms of construction. This results in a considerable reduction in wear and in a reduction in driving energy. This applies in particular if the fact is taken into account that the rolling links can travel with rolling contact on the engaging teeth of the rotating chain star wheel, so that there is no longer the risk of the chain jumping off after a certain pressure point is exceeded, and consequently there is no longer the risk of increased damage. The kinematics are also improved, because the motional clearance of the horizontal links, which can move in relation to each other, can be enforced, as it were. Moreover, a selfcleaning effect is achieved in the region of engagement of the horizontal links between the adjacent rolling links due to the rolling motion of the latter when the teeth of the chain wheel are in engagement, so that contamination due to fine-grained material or fine coal and rock can no longer result in a jamming effect. As a whole, the level of operational reliability is considerably improved and the efficiency of running is improved.

Other preferred features of the invention are listed below. Thus, the invention teaches that the inside diameter of the rolling links is selected so that it is slightly greater than twice the diameter of the engaging horizontal links or of the link curves thereof, so that a controlled extent of motional clearance is ensured between the link curves of adjacent horizontal links which engage in the rolling links, even when the level of contamination is high In this respect, the rolling links perrnit the engaging link curves of the horizontal links, and consequently the horizontal links themselves, to move with a degree of tolerance in the course of a travelling process with rolling contact, in order thus to prevent jamming of the chain links. The rolling links advantageously an outer peripheral face of shallow convexity, which is matched to the flanks of the engaging teeth of the chain star wheel. Moreover, the rolling links may have an inner peripheral face which corresponds to the inner curves of the engaging horizontal links, so as also to be able to run smoothly with rolling contact in relation to the horizontal links or the link curves thereof.

Within the scope of the invention, the horizontal links are guided in the guide rail with an extremely large vertical motional clearance, so that a change of height of adjacent horizontal links in the vertical or rolling links is possible and so that any constraint resulting from the engaging teeth of the chain star wheel is avoided.

The guide rail of the guide unit according to the invention comprises, in the usual manner, a running rail for a running wheel or supporting wheel of the chain star wheel. In this connection, the invention provides for the running rail and the central cross-section of the horizontal links of the round link chain, which horizontal links float on material being conveyed, to be disposed at substantially the same height, so that the running wheel and the chain star wheel or the toothed wheel thereof rotate at the same peripheral speed, and so that it is ensured that the engagement of the teeth of the chain star wheel in the round link chain is achieved without constraint and without jamming.

The invention is explained in greater detail below with reference to the drawings, which are merely schematic illustrations of an example of an embodiment, where: Figure 1 is a perspective illustration of a guide unit according to the invention, wherein the cutting machine is indicated; Figure 2 is a vertical section A-A through Figure 1; Figure 3 shows an area of Figure 1 in the region of two horizontal links and a vertical link which connects the horizontal links; Figure 4 is a partial plan view of Figure 3, showing a vertical link sectioned on one side; and Figure 5 shows Figure 3 during travel with rolling contact.

The drawings illustrate a guide unit for a cutting machine 2 which is disposed on a scraper chain conveyor 1. The basic construction of the guide unit comprises a guide rail 3 with an engagement channel 4 and a round link chain 5 which is mounted in the guide rail 3 and which has horizontal links 6 and which has vertical links 7 constructed as short links. The horizontal links 6 and the vertical links 7 are disposed in the guide rail 3 with a predetermined motional clearance. A driven chain star wheel 8 of the cutting machine 2 engages in the horizontal links 6 and consequently engages in the engagement channel 4 also, which is situated below the round link chain 5. The vertical links are constructed as rolling links 7 with a circular inside diameter Di and a circular outside diameter D3. For the purpose of compensating for tolerance, the inside diameter D of the rolling links 7 is slightly greater than twice the diameter Db of the engaging horizontal links 6 or of the link curves thereof. The rolling links 7 have an outer peripheral face 9 of shallow convexity and have an inner peripheral face 11 which corresponds to the inner curves 10 of the engaging horizontal links 6. In addition, a relatively large vertical motional clearance S-Dh is provided in the guide rail 3 for the horizontal links 6, so that the horizontal links 6 can be displaced by a predetermined vertical distance as a result of the rolling links 7 travelling with rolling contact when the teeth 12 of the chain star wheel 8 are in engagement.

This vertical motional clearance S-Dh can be two to three times the conventional motional clearance, and can amount to 8 to 10 mm.

The guide rail 3 comprises a running rail 13 for a running wheel 14 of the chain star wheel 8.

The running rail 13 and the central cross-section of the horizontal links 6 of the round link chain 5, which horizontal links float on material 15 being conveyed, are disposed at substantially the same height, so that the teeth 12 of the chain star wheel 8 rotate at practically the same speed as that of the running wheel 14. In addition, a side plate 16 is indicated which is attached to the channel of the scraper chain conveyor 1 and which comprises a steel section 17 for limiting the vertical motional clearance of the horizontal links 6 from the outside.

Claims

CLAIMS 1. A guide unit for a mining machine, particularly a cutting machine, disposed on a scraper chain conveyor, comprising a guide rail with an engagement channel and comprising a round link chain which is mounted in the guide rail and which has horizontal links and which has vertical links constructed as short links, wherein the horizontal links are disposed in the guide rail with a predetermined motional clearance and a driven chain star wheel of the cutting machine engages in the horizontal links and in the engagement channel, with the vertical links constructed as rolling links with a circular inside diameter and a circular outside diameter, and with the horizontal links mounted in the guide rail with an oversize vertical motional clearance.
2. A guide unit according to claim 1, wherein the inside diameter of the rolling links is selected so that it is slightly greater than twice the diameter of the engaging horizontal links.
3. A guide unit according to claims 1 or 2, wherein the rolling links have an outer peripheral face of shallow convexity.
4. A guide unit according to any one of claims 1 to 3, wherein the rolling links have an inner peripheral face which corresponds to the inner curves of the engaging horizontal links.
5. A guide unit according to any one of claims 1 to 4, wherein the horizontal links are guided in the guide rail with a large vertical motional clearance.
6. A guide unit, wherein the guide rail comprises a running rail for a running wheel of the chain star wheel, wherein the running rail and the central cross-section of the horizontal links of the round link chain, which horizontal links float on material being conveyed, are disposed at substantially the same height.
7. A guide unit for a mining machine, substantially as hereinbefore described with reference to the accompanying drawings.