US3611531A

US3611531A - Mill roll mountings

Info

Publication number: US3611531A
Application number: US775840A
Authority: US
Inventors: Nicholas A Townsend; Roy R Oxlade
Original assignee: British Iron and Steel Research Association BISRA
Current assignee: British Iron and Steel Research Association BISRA
Priority date: 1967-11-15
Filing date: 1968-11-14
Publication date: 1971-10-12
Anticipated expiration: 1988-10-12
Also published as: GB1240656A; FR1591893A; SE358820B; DE1809261A1

Abstract

A ROLLING MILL WORK ROLL ASSEMBLY COMPRISING A WORK ROLL RELEASABLY SECURED TO THE FREE END OF A DRIVE SHAFT. THE ROLL IS AXIALLY LOCATED BY MEANS OF A FORCIBLY ABUTTED SEAT AND SEATING SURFACE, EACH PERPENDICULAR TO THE ROLL AXIS, ON THE ROLL AND SHAFT. THE ROLL IS RADIALLY LOCATED BY MEANS OF A CO-OPERATING CYLINDRICAL SPIGOT AND CYLINDRICAL RECESS PROVIDED ONE EACH ON THE ROLL AND THE SHAFT. BACKLASH BETWEEN THE ROLL AND SHAFT IS PREVENTED BY ENGAGING KEY AND KEY-WAY MEMBERS PROVIDED ONE EACH ON THE ROLL AND THE SHAFT. THE FORCIBLE ABUTTING OF ROLL AND SHAFT IS PROVIDED BY READILY RELEASABLY MEANS ACTING AXIALLY ONLY TO COMPRESS THE ROLL AGAINST THE SHAFT, AND EXTENDING THROUGH AN AXIAL BORE ON THE WORK ROLL.

Description

191 N. ,A. TOWNSEND ETAL 3,511,531

MILL ROLL uouu'rmcs Filed Nov. 14, 1968 2 Sheets-Sheet 1 21 12 V? F IG. 1

1971 N. A. TOWNSEND EI'AL 3,511,531

MILL ROLL MOUNTINGS 2 Sheets-Sheet 3 Filed Nov. 14. 1968 0m mm qmmw mm Wm mo mm Wm mm Oh L or On 2w 5 O0.

United States Patent Ofice 3,611,531 Patented Oct. 12, 1971 3,611,531 MILL ROLL MOUNTINGS Nicholas A. Townsend, Bexley Heath, Kent, and Roy R. Oxlade, London, England, assignors to The British Iron and Steel Research Association, Buckingham Gate, London, England Filed Nov. 14, 1968, Ser. No. 775,840 Claims priority, application Great Britain, Nov. 15, 1967, 52,086/67 Int. Cl. B30b 3/00 US. Cl. 29129 8 Claims ABSTRACT OF THE DISCLOSURE A rolling mill Work roll assembly comprising a work roll releasably secured to the free end of a drive shaft. The roll is axially located by means of a forcibly abutted seat and seating surface, each perpendicular to the roll axis, on the roll and shaft. The roll is radially located by means of a co-operating cylindrical spigot and cylindrical recess provided one each on the roll and the shaft. Backlash between the roll and shaft is prevented by engaging key and key-way members provided one each on the roll and the shaft. The forcible abutting of roll and shaft is provided by readily releasable means acting axially only to compress the roll against the shaft, and extending through an axial bore on the work roll.

This invention relates to the mounting of a removable rolling mill roll on a shaft arranged to carry that roll in a rolling mill frame.

The invention has particular but not exclusive application to rolling mills for rolling steel or other metal bar or rod stock.

It is desirable, for purposes connected with the mechanics of of the rolling process to adopt as small a diameter work roll as is possible while consistent with other factors such as physical strength and capacity of roll support bearings which may be accommodated in association with a given diameter roll.

Further it is desirable that mill work rolls are removable so that they may be exchanged with different rolls so that a variety of bar sizes and shapes may be rolled on the same mill without difficulty and without undue time delays associated with changing the rolls, and so that worn rolls may be replaced. This inevitably leads to the rolls being removable carried on roll shafts which are rotatably mounted and driven in the mill frame, and the mounting of the roll on such a shaft so as to be readily removable while withstanding the heavy rolling loads without damaging the mounting has been a problem in the past for the mill designer.

It is therefore an object of the present invention to provide a manner of mounting a mill roll upon a shaft in a rolling mill which alleviates the above and other problems.

Accordingly the present invention provides a rolling mill work roll assembly comprising a work roll shaft having a free end face presenting an axial locating spigot and an annular seat disposed radially outwardly of said spigot, said seat being perpendicular to the shaft axis, and a work roll having an axial recess shaped to receive said spigot and an annular seating surface shaped to locate axially against said shaft seat, and releasable means for urging said roll axially against said shaft seat whereby in use the roll is located axially and radially on said shaft.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is a side elevation of a four-high rod mill incorporating a work roll assembly according to the invention,

FIG. 2 is a longitudinal section of a work roll assembly according to the invention, and

FIG. 3 is a cross-section on line AA of FIG. 2.

Referring to FIG. 1 there is shown a four-high rod mill having two

work rolls

10 and 11 which are carried on the frame 12 of the mill respectively in two

arms

13 and 14 which are mutually pivotable about pivot axis 9 so that the roll gap may be adjusted and so as to facilitate ready access to the work rolls. The pivotable mounting is more fully disclosed and claimed in our co-pending patent application of even date herewith entitled Rolling Mills.

The

Work rolls

10 and 11 are carried for rotation in the

arms

13 and 14 respectively on the free ends of

shafts

15 and 16 which are rotatably carried in the

arms

13 and 14 and arranged to be driven in a conventional man her during rolling by way of

universal couplings

17 and 18. The

shafts

15 and 16 are carried in the

arms

13 and 14 in anti-friction rolling element bearings indicated generally at 19 and 20 in a manner disclosed and claimed in our co-pending patent application Ser. No. 775,593 of even date herewith entitled Stock Tension Measurement in Rolling Mills.

The

work rolls

10 and 11 are backed up by back-up or supporting

rolls

21 and 22 which are mounted for rotation, preferably on

arms

13 and 14, and preferably on stub axles as more fully disclosed in our co-pending application Ser. No. 775,668 entitled Rolling Mills." The provision of supporting rolls assists in enabling the diameter of the work rolls to be kept small by assisting in reducing the likelihood of work roll eccentricity due to a heavy work load, with attendant advantages as out lined above.

As shown in FIG. 2, the

work roll shafts

15 and 16 each have a free end face presenting an axial locating spigot 23 and an annular seat 24 disposed radially outwardly of the spigot 23, the seat being accurately perpendicular to the shaft axis. The work rolls 10 and 11 each have an axial recess 25 shaped to receive the spigot 23, and an annular seating surface 26 shaped to locate axially against the seat 24. The co-operation of the spigot in the recess provides radial location for the work roll on the shaft, and the co-operation of the seating surface on the seat provides axial location for the Work roll with respect to the shaft.

The work rolls 10 and 11 each have an axial bore 30 and the

shafts

15 and 16 each have an axial bore 31. A hydraulically expandable hollow bolt 32 extends through the bores 30 and 31. The head of the bolt is keyed and retained at the end of the shaft remote from the work roll by means of a shoulder 33 abutting an annular shoulder 34 formed just within the end of the bore 31. A portion of the associated

universal couplings

17 or 18, or

other means, prevents the bolt 32 from sliding outwardly of the shaft. The work rolls 10 and .11 are retained and urged axially against the

respective shafts

15 and 16 by a retaining nut 40 threaded onto the bolt 32. The inner face of the nut 40 engages a shoulder 41 provided within the roll. A method adopted to mount a

work roll

10 or 11 on its

respective shaft

15 or 16 is as follows. Firstly the work roll is passed over the hydraulic bolt 32 extending from the work roll shaft and the retaining nut 40 is screwed over the threaded end of the hydraulic bolt 32 to bring the work roll up to locate on the spigot 23 of the work roll shaft. The retaining nut 40 is tightened hand tight and the hydraulic bolt 32 is then expanded axially by being pressurised from a source of hydraulic fluid under pressure by way of a port 43 provided in the work roll end of the hydraulic bolt 32. This results in the retaining nut 40 again becoming slack. The retaining nut 40 is then further tightened hand tight, or tighter, to urge the annular seating 26 firmly axially against the seat 24, and the hydraulic bolt 32 is then depressurised to relax into a state of considerable tension and so to retain the work roll firmly located on the shaft by way of the retaining nut 40. In order to remove the

work roll

10 or 11 from its respective shaft, the hydraulic bolt 32 is again expanded, the retaining nut 40 slackened, and then removed. A replacement roll can then speedily be mounted on the still expanded bolt.

In order to prevent the nut 40 from any possibility of its vibrating loose during operation of the mill, a locking means is provided to lock the nut in its tightened position. To this end the nut is provided with opposed radial grooves 50 and 51. A tangential pivot pin 52 spans groove 50 and pivotally mounts a locking arm 53. The threaded end of bolt 32 is castellated as shown at 54. When the nut 40 is tight on the bolt, the locking arm 53 is swung downwardly to assume its locking position shown in FIG. 2 in which it extends through opposed radial slots of the castellation 54 to engage in radial groove 51. Finally a cap 60 is provided which is a press fit onto the end of the work roll and has a peripheral sealing flange 61, whereby to prevent ingress of foreign material into port 43 during use of the rolling mill. Preferably a removable plug (not shown) is provided for port 43'.

The work rolls l and 11 are each provided with a key member in the form of a curved wall 70 concentric with the roll axis and disposed radially outwardly of the seating surface 26. The curved wall 70 extends concentrically of the roll axis to somewhat less than 180 of the roll circumference as shown in FIG. 3.

The work roll shafts l and 16 are each provided with axially extending key way disposed to receive the key member of the associated work roll. The key way is defined circumferentially of the shaft between the two

radial end faces

71 and 72 of an enlarged diameter collar portion 73 of the shaft. The key way extends concentrically of the shaft axis to somewhat more than 180 of the shaft circumference as shown in FIG. 3, and thus an axial key way space 74 is defined between radial end face 72 and radial end face 75 of the curved wall 70. The key way space 74 is wedge shaped and a wedge member 76 is provided that is slightly larger in the circumferential direction than space 74. The wedge member 76 is urged radially inwardly of space 74 by means of a threaded bolt 77 extending through a radial bore 78 in said wedge into a threaded radial bore 79 in the shaft. The head 80 of bolt 77 engages a shoulder 81 within bore 78. It will be appreciated that as bolt 77 is tightened, the wedge member forces faces 72 and 75 circumferentially apart and urges the radially opposed faces 71 and 69 into firm engagement. Each work roll and its shaft are thus securely keyed and pre-loaded against relative rotation, thus substantially preventing any backlash between the shafts and the roll.

It will be appreciated that the described work roll mounting arrangement provides a work roll which is located axially and radially on its shaft and is keyed to prevent backlash. Moreover the roll is so supported as to permit it to be of small diameter and have a relatively large bore, thereby lessening the weight of the roll and permitting it to be readily handled. Moreover the small roll diameter reduces the rolled stock to work roll interface area, thereby reducing the spread of the rolled stock and improving dimensional tolerances in the rolled rod or bar. The described mounting on a free end of a shaft permits ready and speedy access to the roll with consequential replacement and adjustment times.

The described assembly can find particular application in each four-high rod mill of a close coupled twin stand mill, wherein each mill is arranged with its respective Shafts perpendicular to the shafts of the other mill, whereby to eliminate rod twist between the two mills. This arrangement is disclosed in more detail in our two co-pending patent applications of even date herewith and referred to above.

We claim:

1. A rolling mill work roll assembly comprising a work roll shaft and a work roll, said shaft being co-axial with said work roll, said shaft having a free end face presenting a cylindrical locating spigot and an annular seat, said cylindrical spigot and said seat being co-axial with the shaft, said seat being disposed radially outwardly of said spigot, and said seat being perpendicular to the shaft axis, said work roll having a cylindrical recess defined axially therein shaped to receive said cylindrical spigot and having an annular seating surface shaped to abut axially against said shaft seat, wherein there is provided an axially extending key member and an axially extending key-way member disposed to receive said key member, said members being provided one each on said work roll and said work roll shaft, said work roll having an axial bore extending therethrough of less diameter than said cylindrical recess, said work roll having an outer end face, and releasable force applying means extending through said bore for acting only axially between said work roll outer end face and said shaft to urge said work roll axially against said shaft seat, whereby in use the cooperating spigot and recess locates the roll radially on the shaft, the forceably abutted seat and seating surface locate the roll axially of the shaft, and the engaged key and key-way members key the roll and the shaft against relative rotation about their common axis.

2. An assembly according to claim 1 wherein the key member is provided on the roll and the key-way member on the shaft.

3. An assembly according to claim 2 wherein the key member is formed integrally with the roll and the keyway member is formed integrally in the shaft.

4. An assembly according to claim 2 wherein the key member is a curved wall concentric with the roll axis and disposed radially outwardly of said annular seating surface.

5. An assembly according to claim 4 wherein said curved wall extends concentrically of the roll axis to an extent less than the key-way member extends circumferentially of the shaft axis, whereby to define a key-way space, and wherein there is provided a Wedge member and means for urging the wedge member radially inwardly of the shaft into said key-way space whereby substantially to prevent backlash between the shaft and the roll.

6. An assembly according to claim 5 wherein the wedge member has a radial bore and the shaft has a registering threaded bore, and said means for urging the wedge member comprises a bolt engageable in said threaded bore.

7. An assembly according to claim 1 wherein said releasable force-applying means for urging the roll axially against said shaft seat comprises a hydraulically ex- References Cited pandable hollow bolt member extending through said UNITED STATES PATENTS axlal bore in the roll and through an axial bore in the roll shaft; 3. source of hydraulic pressure; means for 325,121 9/1835 Jackson X connecting the source of hydraulic pressure to the interior 5 2,190,371 2/1940 Taylor 28753 X of the hollow bolt and a nut threadably positioned on 23181051 5/1943 Brace 287'53 the bolt.

8. An assembly according to claim 7 including means LEON MACHLIN Pnmary Exammer for preventing the nut from rotating relative to the bolt US Cl. X.R.

when the nut is in its tightened position. 10 287 -52,0l