ROLL STAND

Abstract

A roll stand for the rolling of rolling stock, especially metal products. The roll stand includes at least two chocks for mounting at least one roll, the roll being rotatably mounted in the chocks by its two cylindrical roll necks. A cylindrical neck bushing is arranged on the roll neck with radial play. A rotationally fixed annual axial bearing is axially offset from the neck bushing. The bearing arrangement for the roll necks in the chocks is formed as a plain bearing, preferably a hydrodynamic oil film bearing. When subjected to a load in a rolling process, the neck bushing moves and deforms not only in the radial direction, but also in the axial direction.

Claims

1-19. (canceled)

20. A roll stand for the rolling of rolling stock. especially metal products, comprising: at least two chocks; at least one roll having a roll barrel and two roll necks, at least one of which is cylindrical in shape, the roll being rotatably mounted with their roll necks in the chocks; a cylindrical neck bushing arranged coaxially on the cylindrical roll neck with radial play; wherein the chocks have respective bearing bushings to receive the roll necks of the roll with their respective neck bushings and an annual axial bearing arranged axially offset from the neck bushing; wherein the neck bushing is mounted in axially movable manner between a first abutment in the form of the axial bearing and a second abutment along an axial path a on the cylindrical roll neck.

21. The roll stand according to claim 20, wherein the axial bearing is rotationally fixed in regard to the rotatably mounted roll, in particular, it is firmly joined to the chock.

22. The roll stand according to claim 21, wherein the axial bearing is designed as a plain bearing, especially as an oil film bearing and having preferably an annular base body firmly joined to the chockpreferably in releasable mannerand a bearing race, which is arranged coaxially to the base body on the side of the base body facing toward the neck bushing and is firmly joined to the base bodypreferably in releasable manner.

23. The roll stand according to claim 22, wherein the base body and the bearing race are formed as a single piece.

24. The roll stand according to claim 22, wherein the base body comprises at least one lubricant duct and the bearing race comprises at least one through borein fluidic communication with the lubricant duct for the supplying of lubricant outside of the axial bearing to an annular gap between the bearing race and the neck bushing.

25. The roll stand according to claim 24, wherein an annular lubricant collection space is formed between the base body and the bearing race.

26. The roll stand according to claim 22, wherein the bearing race has a plurality of race segments distributed about its circumference, which protrude in the direction of the neck bushingwith respect to the back side of the bearing race and a radial plane between the base body and the bearing race; and the partial surfaces of each of the race segments facing toward the neck bushing are formed plane parallel to the radial plane and/or positively and/or negatively inclined in relation to the radial plane.

27. The roll stand according to claim 26, wherein partial surfaces of the race segments are arranged adjacent to each other in the circumferential direction of the bearing race such that each time a surface with positive inclination relative to the radial plane is facing toward a surface with negative inclination.

28. The roll stand according to claim 24, wherein the through bore is arranged in the bearing race between a partial surface with positive inclination and a partial surface with negatively inclined surface.

29. The roll stand according to claim 20, wherein the relation holds for the axial path a corresponding to the width of the gap: 1 mma20 mm.

30. The roll stand according to claim 20, further comprising: a feather key arranged between the roll neck and the neck bushing in order to prevent a rotary movement of the neck bushing relative to the roll neck.

31. The roll stand according to claim 20, wherein the second abutment is formed by a shoulder in the surface of the roll neck.

32. The roll stand according to claim 31, wherein an abutment is formed on the inside of the neck bushing to butt against the shoulder in the surface of the roll neck.

33. The roll stand according to claim 20, wherein the neck bushing is situated in the axial direction closer to the roll barrel than is the axial bearing.

34. The roll stand according to claim 20, wherein the at least one roll is a backing roll.

35. The roll stand according to claim 20, wherein the roll stand comprises two backing rolls and two working rolls rotatably mounted between the backing rolls for the rolling of the rolling stock.

36. The roll stand according to claim 35, wherein intermediate rolls are rotatably mounted between the backing and the working rolls.

37. The roll stand according to claim 24, wherein the lubricant duct of the base body is connected to the lubricant supply of the roll stand.

Description

[0019] Four figures are appended to the specification, showing

[0020] FIG. 1 a roll stand;

[0021] FIG. 2 a longitudinal section through a chock with roll mounted therein or with roll neck mounted therein;

[0022] FIG. 3 a bearing race designed according to the invention; and

[0023] FIG. 4 a section through a race segment of the bearing race in the circumferential direction.

[0024] The invention shall now be described in detail with reference to the mentioned figures in the form of exemplary embodiments. In all the figures, the same technical elements are given the same reference numbers.

[0025] FIG. 1 shows a roll stand 100, for example a quarto roll stand with two working rolls 170 for the rolling of rolling stock, especially metal products, and two backing rolls 160 for supporting the working rolls. Each of the rolls has a respective roll barrel 112 and two roll necks 114 by which the respective roll is rotatably mounted in chocks 200 in the roll stand 100.

[0026] The present invention concerns in particular the mounting of the rolls or the roll necks in the chocks. Not all of the rolls or the roll necks in a roll stand need to be mounted according to the present invention. The mounting according to the invention will be used preferably for the mounting of backing rolls; however, the invention is not limited to backing rolls.

[0027] FIG. 2 shows the mounting according to the invention as an example. One will notice a chock 200, also called a bearing housing, with a bearing bushing 210. The bearing bushing spans a cylindrical space for receiving a roll neck 114 of a roll 110. For the present invention, the roll neck 114 is cylindrical. On the roll neck there is shoved a cylindrical neck bushing 120 having radial play. An axial bearing 130 is provided on the side of the neck bushing distant from the roll barrel, offset in the axial direction R. This axial bearing functions according to the invention as a first abutment 140-1 for the neck bushing 120, distant from the roll barrel. Furthermore, the axial freedom of movement of the neck bushing 120 is limited by a second abutment 140-2 near the roll barrel, in addition to the first abutment 140-1. Between these two end stops, the neck bushing is mounted with free axial displacement ability along an axial path a. The path a, that is, the play allowed to the neck bushing 120 in the axial direction R, is in the range of 1 mm to 20 mm, for example. Unlike the bearing bushing 210 which is firmly connected to the chock 200, the neck bushing 120 because of its radial and axial play is free to move in the radial and axial direction. In the circumferential direction, however, the roll 110 is typically secured by a feather key 150.

[0028] The axial bearing 130 according to the invention is designed as a plain bearing, especially as an oil film bearing. It consists of an annular base body 132 preferably firmly joined to the chock 200, but preferably in releasable manner, and a bearing race 134, which is firmly joined to the base body, but preferably in releasable manner. The bearing race is arranged coaxially to the base body on the side of the base body 132 facing toward the neck bushing 120 and is attached to the base body, for example with screws 131. The releasable connection between the bearing race 134 and the base body 132 is advantageous for easy replacement of the bearing race in event of wear and for easy fabrication of the later described lubricant collection space 133. Alternatively or basically, however, the bearing race 134 and the base body 132 may also be formed as a single piece.

[0029] In FIG. 2, furthermore, it can be seen that at least one lubricant duct 136 is formed in the base body 132, being connected to the already present lubricant supply 180 of the roll stand. The lubricant duct 136 enables a supply of lubricant, such as oil, from the lubricant supply 180 via through bores 137 in the bearing race 134 into a ring-shaped gap 400 between the bearing race 134 and the neck bushing 120. Preferably, a ring-shaped lubricant collection space 133 is formed between the base body 132 and the bearing race 134, which advantageously makes possible a homogenization of the pressure buildup in the lubricant in the circumferential direction.

[0030] The second abutment 140-2, near the roll barrel, for limiting the axial freedom of movement of the neck bushing 120, is formed for example by a shoulder in the surface of the roll neck 114, as shown in FIG. 2. A complementary abutment 122 is then formed on the inside of the neck bushing 120 for butting against the shoulder 140-2 in the surface of the roll neck 114.

[0031] FIG. 3 shows the bearing race 134 according to the invention in enlarged perspective detailed representation. It will be noticed that the bearing race 134 has a plurality of race segments 134-1, 134-2, etc., distributed about its circumference. These race segments are elevated with respect to the flat back side 300 of the bearing race 134. In other words: in the installed condition, the back side 300 of the bearing race faces toward the base body 132 and the race segments are formed respectively on the side of the bearing race 134 facing away from the base body 132 and accordingly are elevated from the base body in the direction of the neck bushing. The back side 300 of the bearing race 134 facing toward the base body 132 then forms a radial plane 300. The race segments 134-n form respective elevations with respect to this back side or radial plane.

[0032] In the circumferential direction, said radial segments 134-n preferably alternate with n=1 to N and holes 139. The holes 139 serve for screwing the bearing race 134 to the base body 132.

[0033] Said race segments respectively have partial surfaces 135-1, 135-2 and 135-3, having different inclinations with respect to said radial plane 300.

[0034] FIG. 4 shows a longitudinal section through one such race segment 134-n in a detail view. The horizontal line shown in the lower portion of FIG. 4 represents the surface or the back side of the bearing race 134 facing toward the base body 132. This line also represents the radial reference plane 300. On its end face away from the base body 132, the race segment 134 exhibits a structure which is formed substantially by three different partial surfaces 135-1, 135-2 and 135-3. The partial surfaces 135-1 run substantially parallel to the radial plane 300. They may serve as an engaging or stowage face for the cylindrical bushing outside of rolling operation. The two partial surfaces 135-2 and 135-3 differ in their inclination relative to the radial reference plane 300. While the partial surface 135-2 has a positive inclination relative to the radial reference plane 300, the inclination or gradient of the partial surface 135-3 is negative relative to the radial reference plane 300. The gradient for the two partial surfaces may be 1:100, for example. Preferably, the two partial surfaces 135-2 and 135-3 are formed adjacent to and facing each other by their different inclinations, as shown in FIG. 4.

[0035] Between the two partial surfaces with different inclination there is preferably formed a lubricant pocket 138, having at its bottom the through bore 137, which communicates fluidically with the lubricant duct 136 in the base body 132 of the axial bearing 130. During rolling operation, lubricant enters the through bore 137 in the direction of the arrow, arriving at first in the lubricant pocket 138 and going from here into the annular gap 400 between the bearing race and the neck bushing 120.

[0036] Refer to the description given above with regard to the function of the inclined partial surfaces 135-2 and 135-3 for building up pressure.

LIST OF REFERENCE NUMBERS

[0037] 100 Roll stand [0038] 110 Roll [0039] 112 Roll barrel [0040] 114 Roll necks [0041] 120 Neck bushing [0042] 122 Abutment [0043] 130 Axial bearing [0044] 131 Screw [0045] 132 Base body [0046] 133 Lubricant collection space [0047] 134 Bearing race [0048] 134-1, -2, -3, -n Race segments [0049] 135-1, -2, -3 Partial surfaces of a race segment [0050] 136 Lubricant duct [0051] 137 Through bore [0052] 138 Lubricant pocket [0053] 139 Holes [0054] 140-1 First abutment [0055] 140-2 Second abutment [0056] 150 Feather key [0057] 160 Backing roll [0058] 170 Working roll [0059] 180 Lubricant supply [0060] 200 Chock [0061] 210 Bearing bushing [0062] 300 Radial plane or back side of the bearing race [0063] 400 Annular gap [0064] a Path [0065] R Axial direction