The invention relates to an installation part, i.e., a support housing for supporting an upper back-up roll in a rolling mill stand, typically, for hot rolling or cold rolling of a metal strip. In addition, the invention relates to a method of production of this installation part.
Basically, installation parts for supporting back-up rolls in rolling mill stands are well known in the state-of-the art.
E.g., the publication “Technical report on high-tech modules for rolling mills,” Morgoil Roll-Neck Bearings” by K. Roeingh, 2002, page 4, Figs. I., II., III and FIGS. 1 and 2 discloses a historical review of development of constructions of such installation parts over time.
An installation part for supporting an upper back-up roll in a rolling mill stand is disclosed in an International Application WO 2007/115971. There is disclosed, in the installation part disclosed there, a main bore extending from the drain side to the cambered side of the installation part for receiving a roll journal of the upper back-up roll. The installation part further includes a lubricant receiving space provided on the cambered side in the lower region of the installation part, wherein the lubricant receiving space is associated with two lubricant drain holes arranged mirror-symmetrically with regard to a longitudinal middle plane and which extend from the lubricant receiving space on the cambered side in direction of the drain side of the installation part.
The centers of the lubricant drain holes are spaced from each other by a distance greater than the diameter of the main bore.
Proceeding from this state-of-the art, the object of the invention is to further modify the known installation part and the known method so that in the cross-section of the installation part transverse to the longitudinal direction of the supported roll, recesses can be provided in the right and left lower corners of the installation part.
This object is achieved by the subject matter of claim 1. According to the claim, the installation is characterized in that, viewing in direction of the cambered side, the lubricant drain hole is so arranged that a distance of a center point of the lubricant drain hole to a transverse longitudinal middle plane of the installation part is smaller than/equal to half of the diameter of the main bore and that in the transverse longitudinal middle plane a minimal distance(s) from a counter-surface of an annular seal in the lower region of the installation part to a horizontal tangential plane at top edge of the lubricant drain hole does not exceed a predetermined minimal distance threshold.
The counter-surface of the annular seal corresponds, in the mounted condition of the installation part and the roll, to the outer diameter of the pilot bush extension on which the annular seal is supported.
By taking into account these two claimed criteria it became possible to succeed in greatly reducing the width of the installation part in the lower region at least on the cambered side so that in the right and left corner regions of the installation part, recesses could be provided, e.g., for receiving negatively operating bending cylinders. While the first claimed criterion essentially defines the remaining width of the upper installation part in the lower region, the second criterion insures that the cambered side sealing remains completely functioning. I.e., the produced oil sump is not raised to the extent that the pilot bush extension rotates in this oil sump, which results in leakage.
In the following description, terms “lower,” “upper,” “transverse,” and “horizontal” are used. These terms are used to describe the position of separate technical elements of the installation part or to describe a relative position of separate technical elements relative to each other. When using these terms, one proceeds from a premise that the installation part lies in a horizontal plane. In
According to a first embodiment, the installation part has on its cambered side, a seal retaining element for retaining the annular seal according to the invention, the seal retaining element is formed as one piece with the installation part. In constructions according to the state-of-the art, this seal retaining element is often placed on the installation part as a lid. It is expensive from the manufacturing point of view as the lid must be produced as a separate component. In addition, the mounting and dismounting of the lid is time-consuming and, therefore, is likewise costly. By formation of the seal retaining element together with the installation part as a one-piece cast part, advantageously, separate production of the lid and the time-consuming and costs-extensive mounting and dismounting of the lid are dispensed with.
The annular seal serves for sealing of the installation part with respect to the roll neck or the pilot bush extension. The annular seal also serves for sealing the lubricant receiving space against the body of the upper back-up roll.
According to a further advantageous embodiment, the installation part has two lubricant drain holes which are arranged mirror-symmetrically relative to the transverse longitudinal middle plane in the lower region of the installation part. The provision of two lubricant drain holes insures draining of the lubricant. The formation of the lubricant receiving space according to a further embodiment of the invention, as a circular groove on the cambered side and which has a widening in the lower region of the installation part, has an advantage consisting in that lubricant that exits from a clearance between the bearing bush and the pilot bush can be picked up circumferentially. The advantage of the widening consists in that sufficient space for collected lubricant is available, in particular in the lower region of the installation part where the exiting, under the gravity force, lubricant is collected.
The widening, in the lower region of the installation part on its cambered side, can be formed, from the constructional point of view, without any problem, because there in the lower region no particular large rolling forces are generated. The rolling force acts, with an upper back-up roll and an installation part that receives it, upwardly, i.e., in the upper region of the installation part, as it is known from the state-of-the art.
Typically, the installation part includes a cylindrical bearing received in its main bore.
According to a further embodiment of the invention, a wall of the installation part remote from the cambered side and limiting the lubricant receiving space extends radially smoothly when viewed from a longitudinal axis of the installation part outwardly. It is important that the inner side of the installation part is force and formlockingly connected with the bearing bush over its entire width to a most possible extent. Advantageously, the wall according to the invention, because of its radial smoothness has no projections or noses extending toward the side of the roll body and force-and form-lockingly engageable with the bearing bush. The construction according to the invention insures an optimal force transmission from the neck of the back-up roll over the pilot bush and the bearing bush toward the installation part, this being the case with known projections and noses.
The annular lubricant receiving space and its widening are formed, according to the invention, by being milled in the previously produced cast installation element. The lubricant drain holes can be simply produced by drilling in the cast installation part. Milling and drilling enable geometrically very precise formation of the lubricant receiving space, its widening, and the drain bores
The description is accompanied by six figures, wherein:
The invention will be described in details below with reference to the above-listed figures which show embodiments of the invention. In all of the figures, the same technical elements are designated with the same reference numerals.
It can be seen that the inventive construction provides for recesses 700 the space of which, e.g., can be used for housing of the above-mentioned negatively operated bending cylinders 895.
As shown in
In this view, in particular, the essential criteria for arranging and positioning of the lubricant drain bores 130 are shown. Firstly, a distance d that defines the spacing of the center of a lubricant drain hole 130 from the longitudinal, transversely extending, middle plane LM, is shown. According to the invention, the distance d should be ≦half of the diameter D of the main bore 110 of the installation part, without the bearing bush, in order to be able to so reduce the width of the installation part in the internal region that the desired recesses 700 can be provided. Simultaneously, in the transverse longitudinal middle plane LM, the transverse minimal distance s from the outer surface of the pilot bush extension 232, see
The upper back-up roll 200 has a roll body 210 and a roll neck 220-1. A pilot bush 230 is secured on the roll journal for joint rotation therewith and has a screwed-on pilot bush extension 232 extending in the direction of the roll body. The back-up roll 200, together with the roll neck 220-1 and the pilot bush 230, is rotatably supported in the bearing bush 160. Between the bearing bush 160 and the pilot bush 230, a lubricant film 205 is formed. During rolling operation, lubricant medium is drained from the film into the lubricant receiving space 120 and its widening 120-1. The bearing bush 160 is secured in the main bore 110 of the installation part 100 without possibility of rotation.
Further, in
Number | Date | Country | Kind |
---|---|---|---|
102011087605.7 | Dec 2011 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP12/73786 | 11/28/2012 | WO | 00 |