ROLL LINE UNIT

Abstract

A roll line unit for a continuous casting apparatus includes a roll mantle or roll body surface rotatable relative to a support housing by means of bearing(s). The support housing has a seal(s) located axially outward relative to the at least one bearing and/or seal(s) located axially inward relative to the at least one bearing, and a lubrication system having lubricant reservoir(s) containing lubricant. The support housing has one or more cavities containing lubricant located adjacent to the seal disposed axially outward of the bearing(s) and/or the seal located axially inward of the bearing(s). The lubricant reservoir(s) is/are in fluid communication with the at least one cavity. An actuator within the lubricant reservoir(s) is arranged to move when the volume of lubricant increases in the cavity and/or the reservoir, and/or to push lubricant from the lubricant reservoir into the cavity when the amount of lubricant in the cavity decreases.

Claims

1. A roll line unit for a continuous casting apparatus comprising: a support housing; a roll mantle or roll body surface rotatable relative to the support housing; at least one bearing rotatably connecting the roll mantle or roll body surface to the support housing; at least one seal located axially outward relative to the at least one bearing and/or at least one seal located axially inward relative to the at least one bearing; and a lubrication system including at least one lubricant reservoir containing lubricant; wherein the support housing has at least one cavity containing an amount of lubricant, the cavity being located adjacent to the at least one seal located axially outward relative to the at least one bearing and/or located adjacent to the at least one seal located axially inward relative to the at least one bearing, the at least one lubricant reservoir being in fluid communication with the at least one cavity; and wherein the lubrication system includes at least one actuator disposed within or adjacent to the at least one lubricant reservoir and configured to move when the volume of lubricant increases within the at least one cavity and/or within the at least one lubricant reservoir and/or to move so as to push lubricant from the at least one lubricant reservoir into the at least one cavity when the amount of lubricant decreases within the at least one cavity.

2. The roll line unit according to claim 1, wherein the actuator includes at least one of a spring, a membrane, a spring-loaded device, a mechanical, electrical, gas pressure or hydraulic control means.

3. The roll line unit according to claim 1, wherein the actuator includes a spring-loaded piston.

4. The roll line unit according to claim 1, wherein the lubricant in the at least one cavity is arranged to lubricate at least one of the at least one bearing and the at least one seal.

5. The roll line unit according to claim 1, wherein the at least one bearing is a sealed bearing.

6. The roll line unit according to claim 1, wherein the at least one cavity has a volume in which lubricant is contained, at least seventy percent of the volume being filled with lubricant.

7. The roll line unit according to claim 1, wherein the support housing includes at least one support post and the at least one lubricant reservoir is located inside the at least one support post.

8. The roll line unit according to claim 1, wherein the lubrication system is a re-lubrication-free lubrication system.

9. The roll line unit according to claim 1, wherein the at least one lubricant reservoir is arranged to be filled from outside the support housing.

10. The roll line unit according to claim 1, wherein the lubricant in the at least one cavity is arranged to apply a pressure to at least one seal inside the support housing or to an outer seal configured to seal the inside of the support housing from an exterior environment.

11. The roll line unit according to claim 10, wherein the at least one seal inside the support housing is at least one of a bearing seal, a radial shall seal, a mechanical seal, an axial clamp seal, an O-ring, a washer, a wear sleeve and a V-ring seal.

12. The roll line unit according to claim 1, further comprising at least one sensor configured to determine at least one of an amount of lubricant, a quality of lubricant, a temperature of lubricant and a contamination level of lubricant in one or more parts of the lubrication system.

13. A roll line unit for a continuous casting apparatus comprising: a support housing; a roll mantle or roll body surface rotatable relative to the support housing; at least one bearing rotatably connecting the roll mantle or roll body surface to the support housing; at least one seal located axially outward relative to the at least one bearing or located axially inward relative to the at least one bearing; and a lubrication system including at least one lubricant reservoir containing lubricant; wherein the support housing has at least one cavity containing an amount of lubricant, the cavity being located adjacent to the at least one seal, the at least one lubricant reservoir being in fluid communication with the at least one cavity; and wherein the lubrication system includes at least one actuator disposed within or adjacent to the at least one lubricant reservoir and configured to move in a first direction when the volume of lubricant increases within the at least one cavity and/or within the at least one lubricant reservoir and/or to move in a second, opposing direction so as to displace lubricant from the at least one lubricant reservoir into the at least one cavity when the amount of lubricant decreases within the at least one cavity.

14. The roll line unit according to claim 13, wherein the actuator includes a spring-loaded piston.

15. The roll line unit according to claim 13, wherein the lubricant in the at least one cavity is arranged to lubricate at least one of the at least one bearing and the at least one seal.

16. The roll line unit according to claim 13, wherein the support housing includes at least one support post and the at least one lubricant reservoir is located inside the at least one support post.

17. The roll line unit according to claim 13, wherein the lubricant in the at least one cavity is arranged to apply a pressure to at least one seal inside the support housing or to an outer seal configured to seal the inside of the support housing from an exterior environment.

18. The roll line unit according to claim 17, wherein the at least one seal inside the support housing is at least one of a bearing seal, a radial shaft seal, a mechanical seal, an axial clamp seal, an O-ring, a washer, a wear sleeve and a V-ring seal.

19. The roll line unit according to claim 13, further comprising at least one sensor configured to determine at least one of an amount of lubricant, a quality of lubricant, a temperature of lubricant and a contamination level of lubricant in one or more parts of the lubrication system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will hereinafter be further explained by means of non-limiting examples with reference to the appended schematic figures. It should be noted that the drawings have not been drawn to scale and that the dimensions of certain features have been exaggerated for the sake of clarity. In the figures:

[0033] FIG. 1 shows a continuous casting process;

[0034] FIG. 2 shows a bloom caster comprising four roll line units according to an embodiment of the invention;

[0035] FIG. 3 shows a cross section of one end of a roll line unit according to an embodiment of the invention; and

[0036] FIG. 4 shows a cross section of one end of a roll line unit according to another embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0037] FIG. 1 shows a continuous casting process in which molten metal 10 is tapped into a ladle 12. After undergoing any ladle treatments, such as alloying and degassing, and arriving at the cornet temperature, molten metal 10 from the ladle 12 is transferred via a refractory shroud to a tundish 14. Metal is drained from the tundish 14 into the top of an open-base mold 16. The mold 16 is water-cooled to solidify the molten metal directly in contact with it. In the mold 16, a thin shell of metal next to the mold walls solidifies before the middle section, now called a strand, exits the base of the mold 16 into a cooling chamber 18; the bulk of metal within the walls of the strand is still molten. The strand is supported by closely spaced, water-cooled roll lines 20 which act to support the walls of the strand against the ferrostatic pressure of the still-solidifying liquid within the strand. To increase the rate of solidification, the strand is sprayed with large amounts of water as it passes through the cooling chamber 18. Final solidification of the strand may take place after the strand has exited the cooling chamber 18.

[0038] In the illustrated embodiment the strand exits the mold 16 vertically (or on a near vertical curved path) and as it travels through the cooling chamber 18, the roll lines 20 gradually curve the strand towards the horizontal. (In a vertical casting machine, the strand stays vertical as it passes through the cooling chamber 18).

[0039] After exiting the cooling chamber 18, the strand passes through straightening roll lines (if cast on other than a vertical machine) and withdrawal roll lines. Finally, the strand is cut into predetermined lengths by mechanical shears or by travelling oxyacetylene torches 22 and either taken to a stockpile or the next forming process. In many cases the strand may continue though additional roll lines and other mechanisms which might flatten, roll or extrude the metal into its final shape.

[0040] FIG. 2 shows a bloom caster comprising four roll line units 24 according to an embodiment of the invention of two different lengths which are mounted end to end in on a frame 26 in a rectangular formation. It should be noted that a roll line 20 can contain any number of roll line units 24 arranged in any suitable manner, such as end to end or side by side in a straight line.

[0041] Each roll line unit 24 comprises an exposed roll mantle surface or a roll body surface 28 that is rotatable relative to a support housing 30. The roll mantle surface or roll body surface 28 is arranged to come into contact with steel blooms, for example, which are transported through the frame 26 in a direction at a right angle into or out of the plane depicted in FIG. 2. It should be noted that a plurality of roll line units 24 according to the present invention may be arranged in any suitable manner or configuration in a continuous casting apparatus to facilitate the transport of a strand, billet, bloom or slab of steel. A plurality of roll line units 24 may for example be placed in a single line, optionally mounted on a common shaft, or on a polygonal frame 26 of any suitable size or shape.

[0042] FIGS. 3 and 4 each depict one end of a roll line unit 24 according to an embodiment of the invention. The roll line unit 24 comprises at least one bearing 32 that rotatably connects a roll mantle or roll body surface 28 to the support housing 30.

[0043] It should be noted that a roll line unit 24 according to the present invention may comprise a roll mantle that is mounted on a rotatable shaft in a rotationally fixed manner, each roll mantle having an inner diameter corresponding to an outer diameter of the rotatable shaft. Alternatively, a roll mantle may be arranged to be mounted on a non-rotatable fixed shaft by means of bearings, whereby the roll mantle is arranged to be rotatable with respect to the fixed shaft. In another embodiment of the invention the roll line unit 24 according to the present invention may comprise a roll body comprising an integrated shaft.

[0044] In the illustrated embodiments, the roll line unit 24 comprises a roll mantle 34 fixedly mounted on a rotatable shaft 35 which is rotatable about axis A. The length of a roll mantle 34 or roll body may be 100-1200 millimeters (mm). A roll mantle 34 or roll body is not necessarily cylindrical and does not necessarily have a continuous or a smooth outer surface. It can have any uniform or non-uniform, symmetric or non-symmetric shape, size and/or cross section. The rotatable surface 28 of the roll mantle 34 or roll body may be continuous or non-continuous. The rotatable surface 28 may be even or uneven, and either comprise, or be free from, perceptible projections or indentations.

[0045] The support housing 30 may contain one or more seals 36 located axially outward relative to the at least one bearing 32, as depicted in FIG. 3, and a lubrication system comprising at least one lubricant reservoir 38 containing lubricant. The seals 36 may for example be provided between the shaft 35 and the roll mantle 34 or roll body. The support housing 30 may also contain one or more seals 36 located axially inward relative to the at least one bearing 32, as shown in FIG. 4.

[0046] The support housing 30 comprises at least one cavity 40 containing an amount of lubricant, which is located adjacent to the at least one seal 36. The at least one lubricant reservoir 38 is in fluid communication with the at least one cavity 40.

[0047] The end regions of the roll mantle 34 or roll body are subjected to high loads, high temperatures and high temperature variations, and usually to high humidity, high corrosion and high contamination. By locating a cavity 40 containing lubricant adjacent to a seal 36, an extra barrier against humidity, corrosion and contamination is provided.

[0048] The lubrication system further includes at least one actuator 42 disposed within or adjacent to the at least one lubricant reservoir 38, which is formed as a spring-loaded piston in the illustrated embodiment, configured or arranged to move in a first, preferably “downwards” direction when the volume of lubricant in the at least one cavity 40 and/or the at least one lubricant reservoir 38 increases during the use of the roll line unit 24. The actuator 42 is also configured or arranged to move in a second, opposing, preferably “upwards” direction so as to push or displace lubricant from the at least one lubricant reservoir 38 into the at least one cavity 40 when the amount of lubricant in the at least one cavity 40 decreases.

[0049] A partially compressed spring may for example be placed in contact with a moveable component, such as a piston head 43 (as indicated in FIG. 4) or a part of the lubricant reservoir 38, and the lubricant reservoir 38 may be filled with lubricant on preparing the roll line unit 24 for operation. The actuator spring will then be ready to expand or be compressed further when the roll line unit 24 is in use.

[0050] Alternatively, each actuator 42 may comprise a membrane that is arranged to absorb energy when the volume of lubricant in the at least one cavity 40 and/or the at least one lubricant reservoir 38 increases during the use of the roll line unit 24 and to release energy so as to push lubricant from the at least one lubricant reservoir 38 into the at least one cavity 40 when the amount of lubricant in the at least one cavity 40 decreases. The actuator 42 may include any suitable mechanical, electrical, gas pressure or hydraulic control means.

[0051] The at least one actuator 42 and amount of lubricant in the lubrication system should be selected so that the actuator 42 can accommodate all of the movement expected during the service life of the roll line unit 24.

[0052] The lubricant in the at least one cavity 40 may be arranged to lubricate the at least one bearing 32. Alternatively, the at least one bearing 32 is a sealed bearing, in which case the lubricant in the at least one cavity 40 is not used to lubricate the sealed bearing 32 but instead is arranged to lubricate other components of the roll line unit 24 (e.g., seals 36). A roll line unit 24 according to the present invention may however comprise or include both sealed and non-sealed bearings 32.

[0053] In the illustrated embodiment, the at least one cavity 40 has a volume in which lubricant is contained and may be arranged to be completely full of lubricant during the service life of the roll line unit 24. However, the volume of the at least one cavity 40 may be filled with lubricant up to an amount of at least 70%, or at least 80%, or at least 90%.

[0054] According to an embodiment of the invention, the actuator 42 may be arranged or configured to only move when the volume of lubricant in the at least one cavity 40 and/or the at least one lubricant reservoir 38 increases, or only to move so as to push lubricant from the at least one lubricant reservoir 38 into the at least one cavity 40 when the amount of lubricant in the at least one cavity 40 decreases. For example, in embodiments in which the at least one cavity 40 is not entirely full of lubricant, it may not be necessary for the actuator 42 to move when lubricant in the at least one cavity 40 and/or the at least one lubricant reservoir 38 is heated and expands or when excess lubricant is returned to the lubrication system since lubricant may be capable of expanding or flowing into the free space in the at least one cavity 40.

[0055] The support housing 30 may comprise one or more support posts 30a and at least one lubricant reservoir 38 may be located inside the one or more support posts 30a.

[0056] The lubrication system inside a roll line unit 24 according to the present invention may be a “re-lubrication-free” lubrication system; that is, a lubrication system which contains all of the lubricant needed for the entire service life or use of the roll unit 24 and does not need to be replenished. Alternatively, the roll line unit 24 may comprise at least one lubricant reservoir 38 that is arranged to be filled from outside the support housing 30. A roll line unit 24 according to the present invention may however comprise both re-lubrication-free and non-re-lubrication-free lubrication systems.

[0057] At least one lubricant reservoir 38 may be filled with a semi-solid lubricant, such as grease, which consists of a thickener, emulsified with mineral or vegetable oil and/or another fluid lubricant. Grease possesses a high initial viscosity, which upon the application of shear, drops to give the effect of oil lubrication of approximately the same viscosity as the base oil (or fluid lubricant) used in the grease. Greases are usually applied to mechanisms that can only be lubricated infrequently and where a lubricating oil would not stay in position.

[0058] The lubricant in the at least one cavity 40 is arranged to apply a pressure to one or more seals 36 inside the support housing 30, such as to at least one of the following: a seal, a bearing seal, a radial shaft seal, a mechanical seal, an axial clamp seal, an O-ring or a washer, a wear sleeve or V-ring seal. Alternatively, the lubricant in the at least one cavity 40 may be arranged or configured to apply pressure to an outer seal 36 that seals the inside of the support housing 30 off from its surroundings, i.e. the ambient air or the exterior environment. Further, the lubricant in the at least one cavity 40 may instead be arranged to apply a pressure to any other component(s) inside the roll line unit 24.

[0059] According to an embodiment of the invention a roll line unit 24 may comprise at least one sensor 44 configured to determine the amount of lubricant and/or the quality of the lubricant and/or the temperature of the lubricant and/or a contamination level of lubricant in one or more parts of the lubrication system.

[0060] FIGS. 3 and 4 each shows just one end of a roll line unit 24 according to the present invention. One or both of the ends of a roll line unit 24 may comprise the components shown in FIG. 3 and/or in FIG. 4. Furthermore, it should be noted that the at least one lubricant reservoir 38 need not necessarily be located in the center of a support housing 30, but each reservoir 38 may be located at any position inside the support housing 30, such as closer to one side of a support housing 30. For example, a lubricant reservoir 38 may be arranged to be in fluid communication with at least one cavity 40 located axially outward relative to at least one bearing 32, as shown in FIG. 3, or with at least one cavity 40 located axially inward relative to at least one bearing. 32 as depicted in FIG. 4, or with a plurality of cavities located both axially outward and axially inward relative to at the least one bearing 32. A single cavity 40 may be arranged to be in fluid communication with a plurality of lubricant reservoirs 38.

[0061] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention.

[0062] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0063] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter. The invention is not restricted to the above-described embodiments, and may be varied within the scope of the following claims.