GB2120328A - Compartmented-wheel lock - Google Patents

Abstract

In a compartmented-wheel lock the compartments of which are closed in axial direction by circular side walls (4) of the compartmented wheel (5) and in which the outer rims (7) of the side walls form with the lock housing (2) a seal, the outer rims take the form of cutting edges which, under the influence of the heat arising in operation and with corresponding expansion of the side walls, cut into an annular insert (9) of the housing consisting of softer material, such as plastics, and thereby effect a seal. The outer rim may have two cutting edges. <IMAGE>

Description

SPECIFICATION Compartmented-wheel lock The invention relates to a compartmented or cellular wheel lock the compartments or cells of which are closed in axial direction by circular side walls of the compartmented wheel, the outer rims of which form with the lock housing a seal and for this purpose co-operate with annular inserts of the housing. A seal of this type has in many cases to take into account the fact that, in the case of hot feed material, because of the temperature changes thus occurring, the outer diameter of the frequently very large side walls of the compartmented wheels is subject to considerable variation.

In a known compartmented-wheel lock of this type (DE-GmS 71 32 032), therefore, the outer rims of the side walls are obliquely bevelled on their outside and annular inserts are associated with the bevels, which inserts are arranged in the housing in a manner precluding relative rotation but displaceably in axial direction. They are subject to the action of springs which press against the bevels and thereby effect the seal, in which case they are able to deflect accordingly upon expansion of the side walls. This mode of construction is relatively complicated and is therefore expensive and results in substantial wear in operation, which necessitates frequent replacement of the wearing parts.

In other known compartmented-wheel locks (DE-GmS 69 26 145), Fig. 2, and DE-PS 665 526, Figs. 2 and 3), annular resilient and, optionally, adjustable inserts are provided between the cylindrical outer surfaces of the side walls and the housing, which inserts apply against the outer surfaces and can yield to a greater or lesser extent according to the variations in diameter. In this design too, substantial wear arises in operation, along with the already mentioned disadvantages associated therewith.

The invention is based on the object of devising a design for the sealing means between the side walls of the compartmented wheel and the housing, which offers satisfactory sealing without wear phenomena. It is particularly intended for the compartmented-wheel locks which are subject to compartatively high temperatures in operation because the feed material is very hot.

The invention lies in the fact that the outer rims of the side walls of the compartmented wheel are designed in per se known manner as cutting edges, and in that the annular inserts closely encircle the cutting edges, when the lock is inoperative and at a correspondingly low temperature, and they consist of a compound which is softer than the material of the side walls.

This compound is cut into, upon heating up of the compartmented-wheel lock and with corresponding expansion of the side walls of the compartmented-wheel, by their outer rims in the form of cutting edges, so that annular grooves are formed corresponding to the cutting edges, which grooves remain at the depth of the particular incision.

It is evident that in the compartmented-wheel lock designed in accordance with the invention there is always optimum sealing when the operating temperature is reached. Experience has shown that a compartmented-wheel lock installed in a plant always assumes a certain operating temperature. However, even if it occasionally operates at a lower temperature (for whatever reason), with correspondingly reduced side wails diameter in respect of the small possible choice of cutting-edge angle a quite small clearance arises between the lateral surfaces of the cutting edge and the annular groove and, accordingly, a quite low degree of leakiness is present, which also cannot become fully effective because of the labyrinthine nature of the clearance, so that in any dase completely satisfactory sealing is achieved.

In the compartmented-wheel lock known from DE-GmS 71 32 032, the outer rims of the side walls of the compartmented wheel are admittedly also designed like cutting edges as a result of the bevelling, however, the cutting edges thernselves do not serve for the seal between the side walls and the housing, since they are not even in contact.

In another known compartmented-wheel lock the outer rims of the side walls of the compartmented wheel are likewise designed like cutting edges (DE-GmS 74 17 697). However, these cutting edges also do not serve for sealing between the side walls and housing but merely for avoiding relatively broad outer surfaces of the side walls, between which side walls and the housing it is possible for fragments of the feed material to be jammed. In the case of this compartmented-wheel lock a pronounced seal is not even necessary.

In the subject-matter of the invention, an improvement to the seal can be achieved, if necessary, by providing the side walls of the compartmented wheel at their outer rims with two or more cutting edges, however, this is generally not necessary.

A particular advantage of the development of the compartmented-wheel lock according to the invention is that, irrespective of its subsequent operating conditions, the lock can be massproduced, since it adapts automatically to the particular operating conditions. Thus, there are large installations in which a plurality of compartmented-wheel locks have to operate under quite different temperature conditions. In spite of this, all of the required compartmentedwheel locks can then be manufactured with the same dimensions and tolerances.

A two-component plastics material with particulate metallic inclusions, such as that available commercially under the designation "Belzona-Supermetall", is preferably used as the material for the annular insert. This material is introduced in conventional manner into a corresponding annular recess of the housing and, after curing, is machined to the external dimension of the cold side walls of the compartmented wheel.

The formation of the groove in the plastics ring may be facilitated if the lateral surfaces of the cutting-edge like outer rim of the side walls exhibits slight roughness, so that a weak milling or filing action takes place. It is also possible to apply a light blow to the cutting-edge like outer rim so that the groove is formed by lateral deformation of the material.

This seal can also cope with axial expansion of the compartmented wheel. In the case of simultaneous radial and axial expansion of the compartmented wheel, an annular groove is formed which is sawtooth-shaped in section, which is narrower on the fixed bearing side and wider on the loose bearing side. Because both expansion and contraction always take place in the same or approximately the same relationship of radial to axial direction, the cutting-edge like outer rim of the side walls slides in sealing fashion along the conical groove base.

The invention is illustrated in the drawing on the basis of cut-away portions of a cross-section through a compartmented-wheel lock in two forms of embodiment.

Of the housing of the compartmented-wheel lock there is shown one end wall 1 and a part of the casing 2. 3 denotes a side wall of the feed chute. One of the side walls 4 of the compartmented wheel mounted in the housing is shown, which side walls close in axial direction the compartments situated between the radial compartment walls 5. The outer rim of the side wall 4 is provided with a bevel 6 at the outer end, so that a cutting edge 7 is formed. In the vicinity of the side walls 4, the casing 2 is provided with annular recesses 8 which are filled with a plastics compound. The inner diameter of the rings 9 consisting of this compound corresponds to the outer diameter of the cutting edges 7. Upon heating up under operating conditions, the cutting edges are impressed into the rings 9 and thus effect a good seal between the housing casing 2 and the side walls 4 of the compartmented wheel.

The radial compartment walls 5 are provided at their outer edge with a resilient sealing strip 10.

In the example of embodiment according to Fig. 2, the side walls 4 of the compartmented wheel respectively have two cutting edges 7.

Claims (5)

1. A compartmented-wheel lock, the compartments or cells of which are closed in axial direction by circular side walls of the compartmented wheel, the outer rims of which form the lock housing a seal and for this purpose cooperate with annular inserts of the housing, wherein the outer rims of the side walls are designed in perse known manner as cutting edges, and in that the annular inserts closely encircle the cutting edges, when the lock is inoperative and at correspondingly low temperature, and they consist of a compound which is softer than the material of the side walls.

2. A compartmented-wheel lock as claimed in Claim 1, wherein at their outer rims the side walls of the compartmented wheel are provided with two or more cutting edges.

3. Compartmented-wheel lock as claimed in Claim 1 or Claim 2, wherein the annular inserts of the housing consist of a plastics material having particulate metallic inclusions.

4. A compartmented-wheel lock as claimed in Claim 3, wherein the annular inserts consist of a two-component plastics material which, after being introduced into a corresponding annular groove of the housing, is cured and is then machined to the peripheral diameter of the sidewall cutting edges.

5. A compartmented-wheel lock substantially as herein before described with reference to and as shown in the accompanying drawings.