1. Field of the Invention
This invention relates generally to rolling mill roller guides, and is concerned in particular with an improved means for pre-spinning the guide rollers in advance of the arrival of a mill product therebetween.
2. Description of the Prior Art
As disclosed in U.S. Pat. Nos. 6,151,946 and 4,373,367, it is known to pre-spin the rollers of rolling mill entry guides by impinging a pressurized fluid, typically cooling water, on vanes formed on the exterior sides of the rollers. The vanes are formed on both sides of the rollers so as to permit reversal of the rollers after they have operated for a period of time in one direction of rotation. The drawbacks to such arrangements include the costs associated with forming the vanes on both exterior sides of the rollers, the need to divert cooling water from other locations for dedicated application to the rollers, and the danger that externally applied cooling water may contaminate the roller bearings.
The objective of the present invention is to provide an improved means for driving the guide rollers that avoids the aforementioned drawbacks of the prior art.
In accordance with one embodiment of the present invention, a roller entry guide has mutually spaced annular rollers arranged to contact opposite sides of a product, e.g., hot rolled steel rod, moving at high speed along a path. The rollers are supported on respective shafts by bearings defining axial gaps therebetween. The gaps are surrounded by vanes carried by the rollers. A pressurized fluid, typically an oil mist, is delivered to the axial gaps via passageways in the shafts. The oil mist impinges on the vanes to rotatably drive the rollers, and also serves as a lubricant for the roller bearings.
These and other features and attendant advantages of the present invention will now be described in greater detail with reference to the accompanying drawings, wherein:
With reference initially to
With reference additionally to
A spacer 28 is interposed between the inner bearings races 24a. The spacer is surrounded by a series of vanes indicated typically at 30 and formed on an interior surface of the guide roller 18. An axially extending passageway 32 in shaft 20 is arranged to direct a flow of pressurized fluid to radial passageways 34 communicating with a circular passageway 36 formed by confronting grooves in the shaft 32 and spacer 28. Nozzles 38 in the spacer lead from the passageway 36 and are arranged to direct the pressurized fluid against the vanes 30 to thereby rotatably drive and pre-spin the rollers 18. The pressurized fluid is advantageously an oil mist which serves the added purpose of lubricating the bearings 24.
The embodiment shown in
In light of the foregoing, it will now be understood that in accordance with the present invention, each roller need only be provided with one array of internal vanes. The rollers are rotatably driven by the same pressurized fluid that also serves as the lubricant for the roller bearings. No potentially troublesome external application of cooling water is required, and the internal vanes can serve to rotate the rollers in either direction, thus enabling the rollers to be reversed.
While the internal pre-spinning and lubrication system of the present invention has been described with reference to roller entry guides, it should be understood that the same concept can be utilized to pre-spin and lubricate rollers in other rolling mill applications where rollers are used to guide the hot rolled product along curved paths. One non-limiting example of such an application would be to pre-spin and lubricate the rollers of a rollerized guide directing the hot rolled product into an inclined laying head.