Oil film bearing
View Patent ↗An oil film bearing for supporting a roll neck in a rolling mill, suitable in particular for transmitting high bearing forces when the bearing partners are slightly and slowly moved with respect to each other, has a bearing surface into which are incorporated rods made of a friction-reducing material (e.g., low friction compounds), which extend in a substantially perpendicular direction to the bearing surface. The rods are deformed during heat processing to define a bearing surface. The bearing partner, such as a roll sleeve, rests on the free face of the deformed rods.
1. An oil film bearing for rotatably supporting a roll neck in a rolling mill, said oil film bearing comprising:
a rotating sleeve section having a generally cylindrical outer surface;
a generally cylindrical, fiber-reinforced polymer bushing comprising polytetrafluoroethylene (PTFE) or ultra high molecular weight polymer (UHMW) and providing a generally cylindrical bearing surface, wherein the outer surface of the rotating sleeve section is rotatably supported on a film of oil on the bearing surface; and
a plurality of oil conduits extending through the polymer bushing for supplying pressurized oil between the outer surface of the rotating sleeve section and the polymer bushing to establish the oil film,
wherein the bearing surface is defined by a plurality of deformed rods, wherein each of the plurality of rods is received within an opening in a bearing block, wherein the rods are then heat-deformed in a manufacturing process to define the generally cylindrical bearing surface, with said manufacturing process including:
inserting polymer rods into boreholes of the bearing block,
heating the polymer rods to a temperature resulting in a degree of plasticity,
inserting a pair of generally semi-cylindrical die segments into the bushing, and
outwardly forcing, with an externally powered hydraulic cylinder, the die segments toward the bearing block to deform the heated polymer rods into the generally cylindrical bearing surface.
2. The oil film bearing of claim 1 , wherein the boreholes are perpendicular to the bearing surface or offset relative to the bearing surface.
3. The oil film bearing of claim 1 , wherein the boreholes are closed or open-ended.
4. The oil film bearing of claim 1 , wherein the boreholes include holes of two or more different sizes.
5. The oil film bearing of claim 1 , wherein the boreholes are cylindrical, structured or tapered along their lengths.
6. The oil film bearing of claim 1 , wherein top edges of the boreholes are chamfered.
7. The oil film bearing of claim 1 , wherein the bearing block is formed of a steel alloy.
8. The oil film bearing of claim 1 , wherein the rods are arranged in rows which run perpendicular or at an angle to a preferred direction of movement.
9. The oil film bearing of claim 8 , wherein neighboring rows are offset from each other by an amount greater than or equal to half of the spacing between the rods in a row.
10. The oil film bearing of claim 1 , wherein the bearing surface is covered by a coating to increase surface protection and/or reduce an overall coefficient of friction.
11. The oil film bearing of claim 10 , wherein the coating comprises a nanoparticle coating.
12. The oil film bearing of claim 1 , further comprising a lubricant having an additive which protects an oil system against contamination from bacteria causing bio-corrosion.
13. The oil film bearing of claim 1 , further comprising a sensor provided within the bushing to provide temperature, flow and/or pressure information.
14. The oil film bearing of claim 1 , further comprising sensors to provide information relevant to lubrication conditions, water contamination, or pH conditions.
15. The oil film bearing of claim 1 , further comprising an axial sensor integrated into the bushing to survey and control an axial movement and/or displacement of the sleeve section.