1. Field of the Invention
This invention relates to an improvement in bearings of the type employed to rotatably support the roll necks of rolls in a rolling mill.
2. Description of the Prior Art
In a conventional prior art oil film bearing assembly, as partially illustrted in FIG. 1, the rolling mill roll has a roll body 10 joined to a smaller diameter roll neck 12, with the juncture therebetween being at least partially defined by a curved transition portion 14 and a roll end face 16 lying in a plane perpendicular to the roll axis. An inner bearing component 18, in this case a sleeve, is received on and fixed relative to the roll neck 12 for rotation therewith. The inner bearing component rotates within a bushing 20 contained in a bearing chock 22, and an oil film is maintained hydrodynamically between the sleeve and bushing during normal operation of the mill. The bearing assembly further includes a sealing arrangement 24 interposed between the chock 22 and the roll end face 16 for excluding contaminants such as cooling water and mill scale from penetrating into the bearing, and for preventing oil from escaping from the bearing. The seal arrangement includes an inner seal ring 26 bridging the gap between the inboard end of the inner bearing component 18 and the roll end face. The inner seal ring 26 is normally heat shrunk onto the roll neck, and is desirably in contact as at 28 with the roll end face 16. An O-ring 30 is supported by the outer radial edge of the inner seal ring and is held against the roll end face by a keeper ring 32, the latter being removably attached to the inner seal ring by machine screws 34 or the like. An outer seal ring 36 is fixed to the chock 22. The outer seal ring carries flexible seals 38, and a flexible water guard 40. The seals 38 and water guard 40 are in frictional contact respectively with surfaces of the inner seal ring 26 and keeper ring 32. Much the same arrangement is found in conventional roller bearing assemblies, except that here the inner bearing component comprises the inner bearing race. It is to be understood, therefore, that as herein employed, the term "inner bearing component" is to be construed broadly to include either the sleeve of an oil film bearing or the inner race of a roller bearing.
One problem with the above described prior art arrangement is that as the inner seal ring 26 undergoes thermal contraction during the heat shrinking operation, it exhibits a tendency to pull away from the roll end face 16, thereby creating a gap in place of the contact area 28 shown in FIG. 1. This severely compromises the sealing integrity of the O-ring 30.
Another problem with the prior art arrangement is that in order to replace a worn inner seal ring 26, one must first remove the inner bearing component 18. This can be extremely time consuming and expensive. In cases where the inner bearing component has been shrunk onto the roll neck, it may become necessary to destroy the inner bearing component by cutting it away from the roll neck.
A general object of the present invention is to provide a mounting arrangement for the inner seal ring which obviates or at least substantially minimizes the aforementioned problems.
A more specific object of the present invention is to mount the inner seal ring in a manner such that the thermal contraction which occurs during the heat shrinking operation will urge the inner seal ring towards rather than away from the roll end face. This in turn significantly enhances the sealing integrity of O-rings or the like supported against the roll end face by the inner seal ring.
Still another object of the present invention is to mount the inner seal ring in a manner such that it can be removed and replaced without disturbing the position of the inner bearing component on the roll neck.