Bearing temperature reduction through sleeve modification

Abstract

A novel bushing, such as in a roller for use in a rolling mill, is disclosed in which a feature of length l is introduced on the tapered end of the inner portion of the inner surface of the bushing, in which the introduced feature allows the bushing to deflect with a maximum radial deflection amount of delta as the load increases. The introduced features handle elevated temperature on the inner side of the bushing by allowing the bushing to deflect as the load increases.

Description

[0001] Background of the Invention Technical Field

[0002] The present invention relates generally to the field of rolling mill support bearings, in particular oil film support bearings. More particularly, the present invention relates to the improvement of the temperature profile within the bearing during operation.

[0003] Discussion of related technologies

[0004] Figures 1A-1B depict a known oil film bearing assembly as described in U.S. Patent 4,772,137. The standard in the industry is a cylindrical bushing (sometimes called a bearing) and a cylindrical outer diameter / tapered inner diameter sleeve (sometimes called a journal). The bushing has a close-fitting cylindrical outer diameter in the bearing seat (bearing housing), and the sleeve has an internal taper angle that exactly matches the roller.

[0005] The '137 patent describes a typical rolling mill oil film bearing as follows. A roll 10 has a neck section 12. The neck section 12 can be conical, as shown in FIG. 1(A), or in some alternative configurations it can be cylindrical. A sleeve 14 is received on the neck section 12 and fixed relative thereto. The exterior of the sleeve defines a journal surface 16 of the roll neck. A bushing 18 has an inner bearing surface 20 that surrounds and rotatably supports the journal surface 16. The bushing is contained by and fixed within a bearing seat 22. The bearing seat is closed at the outboard end by an end plate 24 and a cover 26. A seal assembly 28 is disposed between the inboard end of the bearing seat 22 and the roll.

[0006] During normal operation of the rolling mill, when the rolls rotate at a sufficient speed for full hydrodynamic operation, a continuous flow of oil is fed through one of the arrays of passages 29 in the bearing housing, the feed openings 30 in the bushing, and the re-bored holes 32 in the bearing surface 20. From here, the oil enters between the bearing surface 20 and the rotating journal surface 16 to pass through the bearing load zone "Z" and the hydrodynamic length "L H " (the length of the bushing that interacts with the sleeve and supports the oil film) forms a slightly wedge-shaped oil film 34 that is maintained in a fluid-dynamic manner. In Figure 1(A), the load is applied by the roller at "SF". The load is resisted by the force "F" on the bearing seat. The load zone is located on the same side as the resisting force "F". The pressure curve at the load zone is schematically depicted at "P" in Figure 1(A).

[0007] When the rollers are not rotating or are rotating at a speed slower than that required to create and maintain the hydrodynamic oil film 34, conventional hydrostatic devices are used to create the necessary oil film between the journal and the bearing surface.

[0008] At both the inboard and outboard ends of the load zone, oil continuously drains from between the journal surface 16 and the bearing surface 20. The oil draining from the inboard end enters an inboard oil groove 36 enclosed by the seal assembly 28 and by the adjacent surfaces of the bearing seat, bushing, and rollers. The oil draining from the outboard end enters an outboard oil groove 38 enclosed by the end plate 24 and the bearing seat 22. The oil grooves 36, 38 are interconnected by one or more passages 40 drilled through the bearing seat, and the outboard oil groove 38 is connected to a conventional lubrication system (not shown) that filters, cools, and recirculates the oil back to the bearing for reintroduction between the bearing surface 20 and the journal surface 16.

[0009] A conventional sleeve as used on a roll in a rolling mill is shown at 300 in FIG. 3(A). The sleeve has an inner end 301 and an outer end 302, and includes: (a) an outer surface 303 shaped like a cylinder having a sleeve length Ls and a diameter OD, wherein a portion of the sleeve length where the oil film is generated is designated as the hydrodynamic length L H , (b) an inner surface 304 shaped like a cone, including an inner diameter ID at the inner end and a standard cone angle α. In some alternative configurations, the inner surface 304 may also be shaped like a cylinder instead.

[0010] Embodiments of the present invention are improvements over prior art systems and methods. Summary of the invention

[0011] In one embodiment ( Figure 3B In option 1), the present invention provides a sleeve for use in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder, and (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion comprising: (i) an undercut portion having an undercut radius r, the undercut portion being positioned adjacent to an end of the first portion proximate the inboard end; and (ii) a second ramp portion being positioned adjacent to the undercut portion, and wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection amount δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%, and c is preferably 5%.

[0012] In another embodiment ( Figure 3B In option 2), the present invention provides a sleeve for use in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; and (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the second portion includes an undercut radius r, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%, and c is preferably 5%.

[0013] In yet another embodiment (Fig. 3(C) Option 1), the present invention provides a sleeve as used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S-l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion including a second ramp portion positioned adjacent to the first ramp portion, wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection of δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0014] In another embodiment (Fig. 3(C) Option 2), the present invention provides a sleeve as used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0015] In yet another embodiment (Fig. 3(B) Option 1), the present invention provides a method for reducing temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , outer diameter OD and hydrodynamic length L H and (b) providing an inner surface comprising: (1) a length (L S-l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion comprising: (i) an undercut portion having an undercut radius r, the undercut portion being positioned adjacent to an end of the first portion proximate the inboard end; and (ii) a second ramp portion being positioned adjacent to the undercut portion, and wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection amount δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%, and c is preferably 5%.

[0016] In another embodiment (Fig. 3(B) Option 2), the present invention provides a method for reducing the temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; and (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the second portion includes an undercut radius r, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%, and c is preferably 5%.

[0017] In yet another embodiment (Fig. 3(C) Option 1), the present invention provides a method for reducing temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion including a second ramp portion positioned adjacent to the first ramp portion, wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection of δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0018] In another embodiment (Fig. 3(C) Option 2), the present invention provides a method for reducing the temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] According to one or more various examples, the present disclosure is described in detail with reference to the following drawings. The drawings are provided for illustration purposes only, and the drawings merely depict examples of the present disclosure. These drawings are provided to facilitate the reader's understanding of the present disclosure and should not be considered to limit the breadth, scope or applicability of the present disclosure. It should be noted that for clarity and ease of illustration, these drawings are not necessarily drawn to scale.

[0020] 1(A)-(B) depict a known fluid dynamic bearing assembly.

[0021] Figures 2(A)-(C) depict the temperature distribution on the sleeve and bushing under the indicated load / speed combinations.

[0022] 3(A)-(C) depict a standard bushing and then illustrate several embodiments of the present invention depicting features added to the bushing. DETAILED DESCRIPTION

[0023] Although the present invention is illustrated and described in preferred embodiments, the present invention can be manufactured in many different configurations. Preferred embodiments of the present invention are depicted in the drawings and will be described in detail herein, it should be understood that the present disclosure will be regarded as an illustration of the principles of the present invention and the associated functional specifications for its construction, and is not intended to limit the present invention to the illustrated embodiments. Those skilled in the art will envision many other possible variations within the scope of the present invention.

[0024] It should be noted that in this specification, reference to "one embodiment" or "an embodiment" means that the referenced features are included in at least one embodiment of the present invention. Further, separate references to "one embodiment" in this specification do not necessarily refer to the same embodiment; however, such embodiments are not mutually exclusive unless otherwise stated and except as would be apparent to one of ordinary skill in the art. Thus, the present invention can include any various combinations and / or integrations of the embodiments described herein.

[0025] Testing of bearings under various load and speed combinations shows that the oil film thickness is thinner at the inboard side of the bearing (the side closest to the roll surface) than at the outboard end. The difference is typically between 0.05 mm and 0.10 mm. Because the oil film is thinner on the inboard end, the shear rate in the oil film is higher and the bearing and sleeve temperatures also increase.

[0026] Figures 2(A) to 2(C) show the temperature distribution in the sleeve and bushing under the indicated load / speed combinations (i.e., 50RPM & 730 tons, 220RPM & 650 tons, and 290RPM & 510 tons, respectively). The data was obtained by testing a full-size 30"-75KLMorgoil fluid dynamic bearing. Thermocouples are installed in the bushing and sleeve. The sleeve has five thermocouples installed along the axial line, and as the sleeve rotates, the signal is carried out through the slip ring. The fixed sleeve has four axial rows of four thermocouples, two rows are located at + / -10 degrees from the bottom dead center, and two rows are located at + / -45 degrees from the bottom dead center. In the figure at the top of Figure 2(C), the sleeve thermocouple positions are represented by white asterisks and the sleeve thermocouple positions are represented by black circles.

[0027] It can be seen from Figures 2(A) to 2(C) that the temperatures at the inboard side of the bushing and sleeve are higher for all load / speed combinations, particularly in the load zone (+ / - 10 degrees in the bushing) where the film is at its minimum thickness.

[0028] Therefore, there is a need to dynamically adjust the film thickness on the inboard end of the bearing so that as load increases, it will be possible to reduce the temperature in this area. This is important because it can reduce a major type of bearing failure known as inboard edge blow.

[0029] The prior art is replete with examples of attempts to change the shape of a bearing (static member) to conform to the deformed shape of a shaft or housing. The difference with this invention is that the shape of the sleeve and bushing bearing surfaces do not change under no-load conditions—in both cases they are cylindrical. Instead, the new concept is to add manufacturing features to the sleeves to allow them to deflect as load increases, but also to control the total amount of deflection. For purposes of explanation, the maximum amount of radial deflection desired will be calculated as (bearing load rating {F in metric tons} / hydrodynamic length {L H In units of mm})*a, wherein a is selected within the range of 0.02≤a≤0.04 and a is preferably 0.025.

[0030] The present invention provides a feature of length l on the tapered inside diameter (ID) of the inboard end of a bushing (e.g., a bushing used in a rolling mill). A "hinge" feature exists to allow the inboard end to deflect inwardly and the total deflection is set by the offset on that end, which is calculated as (bearing load rating {F in metric tons} / hydrodynamic length {L H In units of mm})*a, wherein a is selected within the range of 0.02≤a≤0.04 and a is preferably 0.025.

[0031] FIG3(B) depicts an embodiment of the present invention. In one embodiment (FIG3(B) Option 1), the present invention discloses a sleeve 300 for use on a roll in a rolling mill, the sleeve having an inner end 301 and an outer end 302, the sleeve comprising: (a) an outer surface 303 shaped like a sleeve having a sleeve length L S , diameter OD, hydrodynamic length L H and an outer diameter OD of the cylinder; (b) an inner surface 304, which includes an inner diameter ID and a taper angle a at the inner end: (1) a length (L S -l) a first portion, the first portion being conical with a first ramp portion 304 (the first ramp portion being a portion of the original cone, which portion being a portion of the inner surface 304); and (2) a second portion of length l, the second portion comprising: (i) an undercut portion 312 positioned adjacent to an end of the first portion close to the inner end, wherein the undercut radius r is preferably defined as 5% of l (the length of the second portion 310), but can optionally be in the range of 2% to 10%; (ii) a second ramp portion 308 positioned adjacent to the undercut portion, wherein the second ramp portion allows the sleeve to deflect with a maximum radial deflection of δ as the load increases. Where l is preferably defined as 25%*L H (hydrodynamic length), but can alternatively be in the range of 20% to 35%. Moreover, the value of δ can preferably be calculated as (bearing load rating {F in tonnes} / hydrodynamic length {L H In mm})*a, where a is selected to be in the range of 0.02≤a≤0.04 and a is preferably 0.025. Alternatively, in option 2 of FIG. 3(B), instead of a taper from the hinge 312 to the medial end, the entire length l is undercut by a constant amount δ, which is calculated in the same manner as option 1.

[0032] In another embodiment (Fig. 3(C) Option 1), the present invention discloses a sleeve 300 for use on a roll in a rolling mill, the sleeve having an inner end 301 and an outer end 302, the sleeve comprising: (a) an outer surface 303 shaped like a roller having a length L S and a cylinder having a diameter OD; (b) an inner surface 304 having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S-1) a first portion having a conical shape with a first ramp portion 304; and (2) a second portion having a length l, the second portion including a second ramp portion 308 positioned adjacent to the first ramp portion 304, wherein the second ramp portion allows the sleeve to deflect with a maximum radial deflection of δ as the load increases. Alternatively, in FIG. 3(C) Option 2, instead of a taper on the second ramp portion 308, the entire length l is undercut by a constant amount δ, which is calculated in the same manner as Option 1 above.

[0033] The bearing surface itself is cylindrical and deflects under load. This deflection can be controlled by manipulating the stiffness of the deflection feature. The length l is the hydrodynamic bearing length L H function.

[0034] In one embodiment (Fig. 3(B) Option 1), the present invention provides a sleeve as used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder, and (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion comprising: (i) an undercut portion having an undercut radius r, the undercut portion being positioned adjacent to an end of the first portion proximate the inboard end; and (ii) a second ramp portion being positioned adjacent to the undercut portion, and wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection amount δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%, and c is preferably 5%.

[0035] In another embodiment ( Figure 3BIn option 2), the present invention provides a sleeve for use in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; and (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the second portion includes an undercut radius r, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected to be in the range of 2%≤c≤10%, and c is preferably 5%. In yet another embodiment (Fig. 3(C) Option 1), the present invention provides a sleeve as used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion including a second ramp portion positioned adjacent to the first ramp portion, wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection of δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0036] In another embodiment (Fig. 3(C) Option 2), the present invention provides a sleeve as used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 200%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0037] In yet another embodiment (Fig. 3(B) Option 1), the present invention provides a method for reducing temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , outer diameter OD and hydrodynamic length L H and (b) providing an inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion comprising: (i) an undercut portion having an undercut radius r, the undercut portion being positioned adjacent to an end of the first portion proximate the inboard end; and (ii) a second ramp portion being positioned adjacent to the undercut portion, and wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection amount δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%, and c is preferably 5%.

[0038] In another embodiment (Fig. 3(B) Option 2), the present invention provides a method for reducing the temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; and (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the second portion includes an undercut radius r, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, length (Ls-l)>length l. In the same embodiment, the undercut radius r is defined as c*length l, wherein c is selected to be in the range of 2%≤c≤10%, and c is preferably 5%.

[0039] In yet another embodiment (Fig. 3(C) Option 1), the present invention provides a method for reducing temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S-l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, the second portion including a second ramp portion positioned adjacent to the first ramp portion, wherein the second ramp portion allows the sleeve to deflect by a maximum radial deflection of δ as the load increases. In one embodiment, δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 20%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0040] In another embodiment (Fig. 3(C) Option 2), the present invention provides a method for reducing the temperature buildup on the inner side of a sleeve used in a roll in a rolling mill, the sleeve having an inner end and an outer end, the method comprising: (a) providing an outer surface shaped like a sleeve having a sleeve length L S , hydrodynamic length L H and an outer diameter OD of the cylinder; (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion having a conical shape having a first ramp portion; and (2) a second portion having a length l, wherein the entire length l of the second portion is undercut by a constant amount δ. In one embodiment, l is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In the same embodiment, the value of l is defined as b*hydrodynamic length {L H}, wherein b is selected to be in the range of 200%≤b≤35%, and b is preferably 25%. In the same embodiment, the length (L S -l)>length l.

[0041] in conclusion

[0042] Systems and methods have been shown in the above embodiments to effectively implement bearing temperature reduction through sleeve modification. Although various preferred embodiments have been shown and described, it will be understood that such disclosure is not intended to limit the invention, but is intended to cover all modifications that fall within the spirit and scope of the invention as defined in the appended claims.

Claims

1. A sleeve for use in a roller of a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) The outer surface is shaped like a sleeve with a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; as well as (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) The length is (L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) a second part having a length of l, the second part comprising: (i) an undercut portion having an undercut radius r, the undercut portion being positioned adjacent an end of the first portion proximate the inner end; (ii) a second slope portion positioned adjacent to the undercut portion, the second slope portion tapering by an amount δ, and The second slope portion allows the sleeve to deflect by a maximum radial deflection amount corresponding to the amount δ as the load increases.

2. The sleeve according to claim 1, wherein: δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H The unit is mm})*a, where a is selected to be in the range of 0.02≤a≤0.

04.

3. The sleeve according to claim 2, wherein: a is 0.

025.

4. The sleeve according to claim 2, wherein: The value of l is defined as b* hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

5. The sleeve according to claim 4, wherein: b is 25%.

6. The sleeve according to claim 1, wherein: The undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%.

7. The sleeve according to claim 6, wherein: c is 5%.

8. The sleeve according to claim 1, wherein: Length, L S -l)>length l.

9. The sleeve according to claim 1, wherein: A bushing is disposed around the outer surface of the sleeve, wherein a gap exists between the bushing and the outer surface of the sleeve, the gap being configured to maintain a hydrodynamically maintained oil film.

10. The sleeve according to claim 9, wherein: The bushing is fixed in the bearing seat.

11. The sleeve according to claim 10, wherein: An end plate and a cover are provided at the outboard end to seal the bushing and the sleeve.

12. A sleeve for use in a roller of a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) The outer surface is shaped like a sleeve with a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; as well as (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) The length is (L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) A second portion having a length l, wherein the second portion includes an undercut radius r, the second portion being positioned adjacent to an end of the first portion proximal to the medial end, wherein the entire length l of the second portion is undercut by a constant amount δ.

13. The sleeve according to claim 12, wherein: δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H The unit is mm})*a, where a is selected to be in the range of 0.02≤a≤0.

04.

14. The sleeve according to claim 13, wherein: a is 0.

025.

15. The sleeve according to claim 13, wherein: The value of l is defined as b* hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

16. The sleeve of claim 15, wherein b is 25%.

17. The sleeve according to claim 12, wherein: The undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%.

18. The sleeve according to claim 17, wherein: c is 5%.

19. The sleeve according to claim 12, wherein: Length (L S -l)>length l.

20. A sleeve for use in a roller of a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) The outer surface is shaped like a sleeve with a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) The length is (L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) a second portion having a length l, the second portion comprising a second slope portion positioned adjacent to the first slope portion, and the second slope portion tapers by an amount δ, wherein the second ramp portion allows the sleeve to deflect with increasing load by a maximum radial deflection amount corresponding to the amount δ, where δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H in mm})*a, where a is selected to be in the range of 0.02≤a≤0.04, where the value of l is defined as b*hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

21. The sleeve according to claim 20, wherein: a is 0.

025.

22. The sleeve according to claim 21, wherein: b is 25%.

23. The sleeve of claim 20, wherein: Length, L S -l)>length l.

24. A sleeve for use in a roller of a rolling mill, the sleeve having an inner end and an outer end, the sleeve comprising: (a) The outer surface is shaped like a sleeve with a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) Length, L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) a second portion having a length l, wherein the entire length l of the second portion is undercut by a constant amount δ; where δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In mm})*a, where a is selected to be in the range of 0.02≤a≤0.04, and where the value of l is defined as b*hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

25. The sleeve according to claim 24, wherein: a is 0.

025.

26. The sleeve of claim 24, wherein: b is 25%.

27. The sleeve of claim 24, wherein: Length, L S -l)>length l.

28. A method for reducing temperature buildup on the inboard side of a sleeve used in a roll of a rolling mill, the sleeve having an inboard end and an outboard end, the method comprising: (a) providing an outer surface shaped like a sleeve having a length L S , outer diameter OD and hydrodynamic length L H Cylinder; as well as (b) providing an inner surface, the inner surface comprising: (1) Length, L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) a second part having a length of l, the second part comprising: (i) an undercut portion having an undercut radius r, the undercut portion being positioned adjacent an end of the first portion proximate the inner end; (ii) a second slope portion positioned adjacent to the undercut portion, the second slope portion tapering by an amount δ, and The second slope portion allows the sleeve to deflect by a maximum radial deflection amount corresponding to the amount δ as the load increases.

29. The method according to claim 28, wherein: δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In mm})*a, where a is selected to be in the range of 0.02≤a≤0.04, and the value of l is defined as b*hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

30. The method of claim 28, wherein: Length, L S -l)>length l.

31. The method of claim 28, wherein: a is 0.

025.

32. The method of claim 28, wherein: b is 25%.

33. The method of claim 28, wherein: The undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%.

34. The method of claim 28, wherein: c is 5%.

35. A method for reducing temperature buildup on the inboard side of a sleeve used in a roll of a rolling mill, the sleeve having an inboard end and an outboard end, the method comprising: (a) providing an outer surface shaped like a sleeve having a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; as well as (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) The length is (L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) A second portion having a length l, wherein the second portion includes an undercut radius r, the second portion being positioned adjacent to an end of the first portion proximal to the medial end, wherein the entire length l of the second portion is undercut by a constant amount δ.

36. The method of claim 35, wherein: δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H in mm})*a, where a is selected to be in the range of 0.02≤a≤0.04, and where the value of l is defined as b*hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

37. The method of claim 36, wherein: a is 0.

025.

38. The method of claim 36, wherein: b is 25%.

39. The method of claim 36, wherein: The undercut radius r is defined as c*length l, wherein c is selected within the range of 2%≤c≤10%.

40. The method of claim 39, wherein: c is 5%.

41. The method of claim 36, wherein: Length (L S -l)>length l.

42. A method for reducing temperature buildup on the inboard side of a sleeve used in a roll of a rolling mill, the sleeve having an inboard end and an outboard end, the method comprising: (a) Providing an outer surface shaped like a sleeve having a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) a length (L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) A second portion having a length of l, the second portion including a second ramp portion positioned adjacent to the first ramp portion, the second ramp portion tapering by an amount δ, wherein the second ramp portion allows the sleeve to deflect with increasing load by a maximum radial deflection amount corresponding to the amount δδ.

43. The method of claim 42, wherein: δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In mm})*a, where a is selected to be in the range of 0.02≤a≤0.04, and the value of l is defined as b*hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

44. The method of claim 43, wherein: a is 0.

025.

45. The method of claim 43, wherein: b is 25%.

46. ​​The method of claim 42, wherein: Length, L S -l)>length l.

47. A method for reducing temperature buildup on the inboard side of a sleeve used in a roll of a rolling mill, the sleeve having an inboard end and an outboard end, the method comprising: (a) providing an outer surface shaped like a sleeve having a length L S , hydrodynamic length L H and a cylinder of outer diameter OD; (b) providing an inner surface having an inner diameter ID and a taper angle α at the inner end, the inner surface comprising: (1) Length, L S -l) a first portion, the first portion being in a conical shape having a first slope portion; and (2) A second portion having a length l, wherein the entire length l of the second portion is undercut by a constant amount δ.

48. The method of claim 47, wherein: δ is defined as (bearing load rating {F in metric tons} / hydrodynamic length {L H In mm})*a, where a is selected to be in the range of 0.02≤a≤0.04, and the value of l is defined as b*hydrodynamic length {L H }, where b is selected to be in the range of 20%≤b≤35%.

49. The method of claim 48, wherein: a is 0.

025.

50. The method of claim 48, wherein: b is 25%.

51. The method of claim 47, wherein: Length (L S -l)>length l.

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