GB2119869A

GB2119869A - Roller for supporting pipelines or other apparatus

Info

Publication number: GB2119869A
Application number: GB08303670A
Authority: GB
Inventors: Friedrich Elsasser
Original assignee: Witzenmann GmbH
Current assignee: Witzenmann GmbH
Priority date: 1982-04-30
Filing date: 1983-02-10
Publication date: 1983-11-23
Also published as: SE448251B; CH660516A5; FR2526096A1; DE3216119C2; NL190203C; FR2526096B1; AT386880B; GB2119869B; NL190203B; NL8300390A; GB8303670D0; FI830604A0; SE8302396D0; ATA37583A; DK154854C; FI830604L; SE8302396L; FI70307B; BE896544A; DK154854B

Abstract

In a support for pipelines or other apparatus, comprising a housing (1) in which at least one rotatable component (6) is mounted between two walls (2,3) on a shaft (4) of stainless steel or with a rust-resisting coating, by way of at least one sleeve (5) with slide bearing properties, the shaft is prevented from being displaced axially by a sleeve (7,8) of stainless steel receiving the respective end of the shaft and inserted into a bore in the wall at at least one end of the shaft, one end of the sleeve being formed as a collar-shaped enlargement (9,10) and the other end being clamped around the end of the shaft. This structure avoids the formation of fretting corrosion between the shaft and the bearing. <IMAGE>

Description

SPECIFICATION Movable support for pipelines or other apparatus This invention relates to a movable support for pipelines or other apparatus, of the type comprising a housing, in which at least one rotatable or pivotable component is mounted between two walls on a shaft of stainless steel or with a rust-resistant coating, where appropriate by way of. at least one sleeve with slide bearing properties, for example a sleeve of polytetrafluoroethylene, and the shaft is prevented at its ends from being displaced axially by way of means cooperating with bores in the walls.

In connection with known axial locking arrangements of this type in roller bearings for pipelines or other apparatus, resilient suspended attachments with a constant supporting force, or suspended attachments in the form of pendulums, the shaft is prevented from being axially displaced in wall bores in a steel housing or components consisting of steel by circlips fitted on to the shaft outside the wall or by split pins inserted into bores in the shaft, it being further necessary to insert washers between the circlips or split pins respectively and the walls so that the corrosion protection or the housing cannot be damaged by the circlips or split rings respectively.

The known design has however, numerous disadvantages. In the first place, in the case of external corrosive action, the bearing of the shaft in the housing can lead to the formation of fretting corrosion, and can penetrate to the slide bearing of the component mounted on the shaft and there lead to an impairment of the bearing properties or destroy the slide bearing.

Secondly, the axial locking arrangement by circlips, which owing to their resilient properties must consist of material which is likewise not completely rust-resistant, eventually leads to corrosion and to the shafts no longer being axially locked with the necessary degree of reliability. If an axial locking arrangement by split rings is utilized, corrosionresistant materials could be chosen for the split rings, but these materials would adversely affect the manufacturing costs of the roller bearing on account of their special production.

Furthermore, the length of the shafts which consist of corrosion-resistant or corrosion-protected and thus expensive material must be made so great that sufficient space remains outside the housing or the walls of the housing supporting the shaft respectively to provide a corresponding groove for the circlips or a corresponding bore for the split rings at the ends of the shaft and also to leave space for the washers between the circlip or split ring respectively and the housing wall. In addition, production expenditure is required for both ends of the shaft, which is particularly substantial in the case of the known complicated finishing of stainless steel.

In the course of assembly a disadvantage additionally arises in the case of the ends of the shaft finished at both ends in that the irregularities in the case of the groove orthe bore at the ends of the shaft may damage the bearing sleeve or sleeves of the mounted component during the insertion of the shaft into the component and also corrosionprotection means possibly provided at the bores in the walls. It has therefore been necessary until now to trim the grooves or bores provided at the ends of the shaft extremely carefully and rigorously, which is likewise difficult from the manufacturing point of view.

Finally, the known axial locking means have the disadvantage that they can be easily loosened or removed, while it is necessary for pipelines in long-distance heating apparatus to have axial locking arrangements which must operate reliably for decades and which may not easily be loosened maliciously.

The present invention aims to provide a modified axial locking arrangement in a movable support for pipe-lines or other apparatus of the type described above such that the formation of rust, in particular fretting corrosion, is prevented, and furthermore that machining the ends of the shaft is largely dispensed with. It is desired that the length of the shaft may be substantially reduced so as to produce a more inexpensive, maintenance-free structure as a whole, and finally the axial locking arrangement is to be desirably durably constructed in such a way that it cannot be removed without special steps being taken.

The present invention provides a movable support for pipelines or other apparatus, comprising a housing, in which at least one component is mounted between two walls on a shaft of stainless steel or with a rust-resistant costing, where appropriate by way of at least one sleeve with slide bearing properties, and the shaft is prevented at its ends from being displaced axially by way of means cooperating with bores in the said walls, wherein a sleeve of stainless steel receiving the respective end of the shaft is inserted into the wall bore at at least one end of the shaft, the stainless steel sleeve resting against the wall on the side of the wail facing the component with a radial collar-shaped enlargement, and the free end of the stainless steel sleeve facing away from the component being formed as a closed, continuous cylinder, the said free end being in positive mesh engagement with the end of the shaft.

The construction according to the invention ensures that fretting corrosion can no longer occur between the ends of the shaft and the walls supporting it. The ends of the shaft are thus mounted in a manner which can no longer adversely affect the bearing of a component mounted rotatably or pivotably on the shaft. In addition, the shaft may now be pre-fabricated in a smooth form in such a way that during fitting it can no longer damage or impair the bearing sleeve or sleeves of the component mounted rotatably or pivotably, and this makes assembly considerably easier.

By means of the invention it remains possible to produce the housing or the walls respectively from normal and thus inexpensive steel. Furthermore, the collar-shaped enlargement of the sleeves replaces the previously required thrust washers of high-grade steel towards the walls, so that a simplified construction and a reduction in costs are achieved.

Finally, the construction of the end of the sleeve as a closed, continuous cylinder and its positive en gagementwith the end of the shaft results in a locking arrangement which cannot readily be damaged. In fact force must be used to release the axial locking arrangement formed in this way.

If the axial locking arrangement is constructed in such a way that the free end of the sleeve is radially flanged over the end of the shaft towards the inside for the purpose of axial locking, then it is possible to limit the length of the shaft practically to the dimension given by the distance between the walls including their material thickness, finishing processes no longer being necessary on the shaft and there being a corresponding saving of material as the shaft is made shorter than in the known art.

In another case the free end of the sleeve may be radially flanged over towards the inside into a peripheral groove at the end of the shaft for the purpose of axial locking, and thus it becomes possible to carry out this step at only one end of the shaft so that the necessity of finishing the shaft is still reduced to half compared to the known art and, in addition, it again becomes possible to make the shaft shorter, as the shaft need only be so long on the other, non-finished side that it may be supported in the housing.

Furthermore, it is possible in all cases for the shaft, if it has to be pushed through the components to be mounted and its bearing sleeve, to be made with smooth walls, so that damage to the bearings cannot occur. In addition, it has been found that the bearing and assembly of the shaft is more inexpensive and simpler despite the sleeves provided than the steps involved with the known axial locking arrangement.

In all the cases described above it may be advantageous for a thrust washer of polytetrafluoroethylene to be interposed between the mounted component and the adjacent wall or collarshaped enlargement respectively of the sleeve. In this case it is advantageous if the thrust washer is integrally joined to the sleeve with slide bearing properties by which the mounted component is rotatably mounted on the shaft.

Finally, it may be advantageous for the collarshaped enlargement of the sleeve to have a cylindrical extension starting from its periphery and enclosing the thrust washer. This extension which may be provided without difficulty is used to protect the bearing in the region of the thrust washer from dirt penetrating from the outside.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which Figure 1 shows a first embodiment of the invention with a roller bearing with a cylindrical bearing roller, viewed in section through the bearing axis; and Figures 2 and 3 are views similar to Figure 1 of further embodiments of the invention.

For reasons of simplicity and clarity, reference is made only to designs -of roller bearings of pipelines or other apparatus although the invention is nevertheless applicable to other forms of movable support as previously defined.

Figure 1 shows in section a roller bearing housing 1 with walls 2, 3, in bores of which a shaft 4 is received, on which shaft is rotatably mounted by way of bearing sleeves 5 a roller 6 on which is supported a load (not shown) in the form of a pipe for example. In this and also in the following embodiments the roller is represented as a cylindrical roller. The roller may, of course, also be a tapered roller, as known perse in the case of roller bearings for specific purposes of use.

The shaft 4 is mounted in the bores of the housing walls 2 and 3 by way of sleeves 7 and 8 of stainless steel, which abut against the walls on the side thereof facing the roller 6 with a radial, collar-shaped enlargement 9 and 10 respectively. The ends of the sleeves 7,8 on the side of the walls 2,3 remote from the roller are flanged over the ends of the shaft 4, as shown in the finished state in the left-hand side of Figure 1, while the state before flanging-over is shown in the right-hand side. Byflanging over the free ends of the sleeves 7, 8 the shaft 4 is gripped and secured in the axial direction relative to the housing 1 and the walls 2,3 respectively.By virtue of the fact that the sleeves 7,8 consist of high-grade steel, the housing 1 may be made of ordinary steel without fretting corrosion occurring between the housing 1 and the shaft 4. In addition, the length of the shaft 4 may practically match the distance between the walls 2,3 since a projecting end is no longer necessary for mounting fastening means.

By virtue of the fact that the sleeves 7,8 have collar-shaped enlargements 9, 10, the roller 6 is provided with a flat abutment plane, against which it may be supported by way of thrust washers 11 and 12 respectively of polytetrafluoroethylene.

One of the sleeves 7,8 in its state before fitting together with the integrally formed collar 9, 10 is illustrated in detail in Figure 1 beneath the sectional view.

The roller 6 shown by way of example in Figure 1 is assembled in a simple manner in that after inserting the sleeves 7, 8 the shaft 4 is pushed through the roller 6, whereupon the free ends of the sleeves 7, 8 are flanged over towards the inside. In this way the roller 6 and its shaft 4 are secured axially in a corrosion-resistant manner, without their being any risk of damage from scratching when the shaft 4 is inserted through the bearing bore of the roller 6 and its sleeves 5. Finally, the flanging-over of the sleeves 7,8 provides an axial locking arrangement which is not readily reversible, so as to prevent malicious or careless dismantling of the axial locking arrangement.

In the case of the embodiment according to Figure 2 the shaft 20 is provided at only one end with a peripheral groove 21, into which a sleeve 22 inserted into the wall 23 is flanged over, thereby securing or fixing the shaft 20 in the axial direction. The sleeve 22 has, in its turn, a radial collar 24 inside the wail 23.

For the purpose of secure axial locking the sleeve 22 is bulged axially, as may be seen in the lower side of the shaft Figure 2.

In this way the right-hand, plain end 25 of the shaft may be pushed through the bearing of the roller 26 during assembly, without there being any risk-of damage. The plain end 25 is then mounted in an open sleeve 41 which is plain towards the outside and which in turn is disposed in the associated wall 42 without additional steps being necessary for the purpose of axial locking.

In the present case bearing sleeves 27, 28 for the roller 26 are integrally joined to thrust washers 29,20 respectively, the thrust washer 29 bearing against the collar 24 of the sleeve 22, while, in the case of the thrust washer 30, a washer 31 of stainless steel is interposed facing the housing wall 42.

Figure 3 shows a further embodiment similar to those which have been described with reference to Figures 1 and 2. In the embodiment shown in Figure 3, each sleeve 32,33 has a respective cylindrical extension 38, 39 which starts from its respective radial collar 34,35 and encloses a respective thrust washer 36,37 and by means of which the thrust washers 36,37 and thus the bearing of the roller 40 are protected from dirt from the outside.

Claims

1. A movable support for pipelines or other apparatus, comprising a housing, in which at least one component is mounted between two walls on a shaft of stainless steel or with a rust-resistant coating, where appropriate by way of at least one sleeve with slide bearing properties, and the shaft is prevented at its ends from being displaced axially by way of means cooperating with bores in the said walls, wherein a sleeve of stainless steel receiving the respective end of the shaft is inserted into the wall bore at at least one end of the shaft, the stainless steel sleeve resting against the wall on the side of the wall facing the component with a radial collar-shaped enlargement, and the free end of the stainless steel sleeve facing away from the component being formed as a closed, continuous cylinder, the said free end being in positive mesh engagement with the end of the shaft.

2. A support as claimed in Claim 1, wherein the free end of the stainless steel sleeve is radially flanged over the end of the shaft towards the inside for the purpose of axial locking.

3. A support as claimed in Claim 1, wherein the free end of the stainless steel sleeve is radially flanged over towards the inside into a peripheral groove at the respective end of the shaft for the purpose of axial locking.

4. A support as claimed in Claim 3, wherein the cylindrical part of the stainless steel sleeve projecting outwards beyond the respective wall is bulged in the direction of the wall after flanging over.

5. A support as claimed in any of Claims 1 to 4, wherein a thrust washer of polytetrafluoroethylene is interposed between the said component and the adjacent wall or collar-shaped enlargement respectively of the stainless steel sleeve.

6. A support as claimed in Claim 5, wherein the thrust washer is integrally joined to a said sleeve with slide bearing properties.

7. A support as claimed in any of Claims 1 to 6, wherein the said collar-shaped enlargement of the stainless steel sleeve has a cylindrical extension starting from its periphery and enclosing a thrust washer.

8. A support as claimed in any of Claims 1 to 7, wherein the said sleeve with slide bearing properties is made of polytetrafluoroethylene.

9. A support according to Claim 1, substantially as herein described with reference to, and as shown in, Figure 1, Figure 2 or Figure 3 of the accompanying drawings.