GB2076481A

GB2076481A - A Roll Neck Sealing Arrangement

Info

Publication number: GB2076481A
Application number: GB8114539A
Authority: GB
Original assignee: MORFAN CONSTRUCTION CO
Current assignee: MORFAN CONSTRUCTION CO
Priority date: 1980-05-22
Filing date: 1981-05-13
Publication date: 1981-12-02
Also published as: CA1171111A; ES8300395A1; GB2076481B; IT1170987B; MX153026A; FR2482878B1; BR8103168A; ES501895A0; DE3119951A1; FR2482878A1; BE888908A; JPS5931965Y2; IT8148499A0; JPS56171463U

Abstract

In a rolling mill, for use in combination with a roll neck 9 surrounded by a bearing sleeve 7 fixed thereto, the bearing sleeve 7 being journalled for rotation in a non- rotatable bushing 1a contained in a bearing chock 1, with the roll neck 9 having a tapered section 9a leading from the neck portion surrounded by the sleeve 7 to an end face on the roll barrel 8, and with lubricant being provided between the bearing sleeve 7 and bushing 1a, a seal assembly is provided surrounding the tapered roll neck section 9a and fixed relative to the bearing chock 1. A circular flexible seal 10 is mounted on the tapered roll neck section 9a for rotation therewith. The flexible seal has a flange 11 extending outwardly therefrom into sealing contact with an adjacent surface 6 of a seal end plate 3. An outer seal ring 3a is fixed relative to the seal end plate 3. The outer seal ring 3a has a cylindrical inner surface cooperating with the seal end plate to define a circular cavity 20 opening towards the end face of said roll barrel 8. A seal inner ring 21 has an inner portion 21c abutting the flexible seal, an outer peripheral portion 21a protruding into the aforesaid cavity, and lips 25, 24 sealingly contacting the roll end face and the inner cylindrical surface on the outer seal ring 3a. <IMAGE>

Description

SPECIFICATION Roll Neck Seal This invention relates generally to sealing arrangements and is concerned in particular with an improved neck seal for rolls in a rolling mill.

A conventional roll neck seal is iliustrated in Figure 1, wherein the seal components include a neck seal f and an inner seal ring g The seal fis fitted onto the roll neck c between the roll barrel b and a sleeve d. The sleeve d is keyed to an extension of the roll neck for rotation therewith within a non-rotatable bushing a'. The bushing a' is in turn contained within a bearing chock a.

During milling operation, lubricating oil is supplied continuously between the sleeve d and the bushing a'. A seal end plate e is fixed to the chock a at a location surrounding the neck seal f. The seal end plate has a rigid radially inwardly extending flangejlocated between two oppositely sloping shoulders k, I.The neck seal f has resilient radially outwardly extending flanges h, iwhich slidingly contact the shoulders k, I.

One problem with this type of arrangement is that when the roll b undergoes axial shifting (from right to left or vice versa as viewed in Figure 1) relative to the chock a, the relationship of the flexible flanges h, i relative to their respective seal end plate shoulder, /will change. For example, one flange will bear against its respective shoulder more tightly with an accompanying increase in friction and wear, whereas the fit between the other flange and its shoulder will become less tight, with the danger that sealing will be adversely affected. Furthermore, because of the rigid flanged on the seal end plate e, the neck seal fmust be deformed during installation into a generally heart-shaped pattern.This in turn precludes the use of high strength inner reinforcing elements, making it necessary to resort to more flexible lower strength elements such as for example the coiled spring m shown in the drawing Such lower strength reinforcing elements may not always be able to resist centrifugal forces generated by high speed rotation of the roll neck c.

Another problem with the conventional arrangement is that the sealing ring o between the seal inner ring g and the end face of the roll barrel b is relatively fragile and is thus frequently damaged during disassembly of the seal.

A general objective of the present invention is to avoid the above-mentioned problems. To this end, the rigid radially inwardly extending flange on the seal end plate has been eliminated, and the seal end plate shoulders have been converted to a single continuous cylindrical surface. Thus, it is no longer necessary to distort the neck seal during assembly, and its outwardly extending radial flanges are in substantially constant frictional contact with the surrounding cylindrical shoulders, regardless of the extent to which the roll neck ultimately undergoes axial shifting.

Additionally, the seal inner ring is at least partially enveloped by an elastic coating having integral sealing lips which sealingly engage the roll end face as well as other components to be hereinafter described in greater detail, thereby providing a more damage-resistant arrangement capable of undergoing repeated disassembly and assembly.

In the accompanying drawings, Figure 1 is a view in cross-section of a conventional roll neck seal for a rolling mill; and Figure 2 is a view similar to Figure 1 showing one example of the present invention.

Referring to Figure 2, a bearing chock 2 is shown defining a hole 2. A seal end plate 3 is fitted on the end of the chock, with an O-ring 5 positioned therebetween to ensure a fluidtight seal. The seal end plate 3 has an inner continuous cylindrical surface 6 which is slidingly contacted by a flexible flange 11 extending outwardly from a neck seal 10. The neck seal is mounted on the tapered section 9a of the roll neck 9. A sleeve 7 is keyed to the roll neck 9 for rotation therewith. The sleeve 7 is journalled for rotation in a nonrotatable bushing 1 a contained by the chock 1.

During operation, lubricating oil is supplied continuously between sleeve 7 and bushing 1 a.

The neck seal 10 is made of rubber or a similar elastic material such as soft synthetic resin. The base portion 1 3 of the neck seal has a tapered hole 12, the taper being approximately the same as that of the neck portion 13, with an inner peripheral groove 1 lea for accommodating a coiled spring 1 b which resiliently urges the flange outwardly into frictional sealing contact with the surrounding cylindrical surface on the seal end plate 3. The base portion 13 of the neck seal is further strengthened by an embedded reinforcing ring 14 having a generally L-shaped cross-section. The embedded portion of the reinforcing ring is generally cylindrical and arranged coaxially with the seal body. The exposed radial flange 1 4a of the reinforcing ring abuts the end of the sleeve 7.

The neck seal 10 is further provided with an inner flange 1 5 held tightly against the tapered roll neck surface 9a by another small diameter spring 16. The opposite end of the seal body further includes another flange 1 7 also arranged to tightly surround the tapered roll neck section 9a. A flinger 1 8 extends angularly outwardly from the base portion 1 3 between the end of the bushing 1 a and the adjacent portion of the seal end plate 3.

An outer seal ring 3a of generallytL-shaped cross-section is secured to the seal ënd plate 3 as at 1 9 and cooperates therewith to define a circular cavity 20 opening towards the roll end face and into which protrudes the peripheral end portion 21 a of the seal inner ring 21. The seal inner ring 21 is appropriately shaped to further provide an intermediate portion 21b extending generally parallel to the end face of roll 8, and an inner portion 21 c having its inner edge received in a notch partially defined by the flange 17 on the base part 13 of the neck seal 10.

In the embodiment herein chosen for purposes of disclosure, the seal inner ring 21 is covered at least partially with a relatively thin coating 23 of elastic material such as rubber which is integrally fused thereto. The coating 23 at the outer peripheral portion 21a of the seal inner ring provides sealing lips 24 which sealingly engage the interior cylindrical surface of the outer seal ring 3a. This inner cylindrical surface preferably is arranged coaxiallh with the cylindrical surface 6 on the seal end plate 3. Additionally, the covering 23 is provided with a plurality of protrusions 26 which resiliently contact the end face of the roll 8, as well as with one or more lips 25 which establish a fluid-tight seal between the seal inner ring 21 and the roll end face.

In light of the above, it will be understood that the neck seal 10 is firmly seated on the tapered portion 9a of the roll neck by virtue of the engagement of the radial flange portion 1 4a of reinforcing element 14 with the end of the sleeve 7. The neck seal 10 is in turn firmly seated against the seal inner ring 21, the latter having its inner portion 21 c firmly received in the notch partially defined by flange 17. The frictional interengagement between the inner portion 21 c of the seal inner ring and the neck seal 10 when combined with that of the protrusions 26 contacting the end face of the roll 8 is sufficient to overcome any frictional resistance encountered as a result of the sealing lips 24 being in contact with the outer seal ring 3a.Thus, slippage of the seal inner ring 21 relative to the neck seal 10 and/or the roll 8 is avoided. The additional sealing lips 25 provide an improved fluid-tight seal between the seal inner ring 21 and the end face of the roll 8. The uninterrupted cylindrical surface 6 on seal end plate 3 enables the flange 11 to experience substantially constant contact regardless of the extent to which the roll neck may undergo axial shifting. The absence of any rigid inwardly extending flange on surface 6 makes it unnecessary to distort the neck seal 10 during assembly and disassembly, and this in turn makes it possible to employ higher strength reinforcing elements such as the embedded metal ring 14. With higher strength reinforcing elements, centrifugal force is more effectively resisted, thereby ensuring that slippage between the neck seal 10 and the tapered roll neck section 9a is avoided.

Claims

1. A seal assembly for use in a rolling mill in combination with a roll neck surrounded by a bearing sleeve fixed thereto, the bearing sleeve being journalled for rotation in a non-rotatable bushing contained in a bearing chock, with the roll neck having a tapered section leading from the neck portion surrounded by the sleeve to ane end face on the roll barrel, and with lubricant being provided between the bearing sleeve and bushing, the seal assembly comprising: a circular seal end plate surrounding the tapered roll neck section and fixed relative to the bearing chock, a circular flexible seal mounted on the tapered roll neck section for rotation therewith, the flexible seal having flange means extending outwardly therefrom into sealing contact with an adjacent surface of the seal end plate, an outer seal ring fixed relative to and having a cylindrical inner surface cooperating with the seal end plate to define a circular cavity opening towards the end face of the roll barrel, a seal inner ring having an inner portion abutting the flexible seal and an outer peripheral portion protruding into the cavity, and lip means on the seal inner ring for sealingly contacting the roll end face and the inner cylindrical surface on the outer seal ring.

2. The seal assembly of claim 1 wherein the said adjacent surface of the seal end plate is cylindrical and coaxial with the cylindrical inner surface on the outer seal ring.

3. The seal assembly of claim 1 wherein the seal inner ring is a metallic element, and wherein the lip means are integrally formed as part of an elastic covering applied to the inner seal ring.

4. The seal assembly of claim 1 further comprising a metallic reinforcing ring at least partially embedded in the flexible seal, the reinforcing ring having an exposed flange engageable with the sleeve.

5. A seal assembly according to claim 1 and substantially as herein described with reference to Figure 2 of the accompanying drawings.