Improved sleeve reduces bearing temperature

Abstract

A novel sleeve as used in rolling mill rolls is disclosed in which a length l feature is introduced to the tapered end of the inner portion of the inner surface of the sleeve, the feature introduced allowing the sleeve to deflect as the load increases with a maximum radial deflection of δ. The feature introduced accommodates the temperature rise inside the sleeve by allowing the sleeve to deflect as the load increases.

Description

[Technical field]

[0001] The present invention relates generally to the field of rolling mill backup bearings, and more particularly to improving the temperature profile within the bearings during operation. [Background technology]

[0002] Figures 1(A) and 1(B) show a known oil film bearing assembly as described in US Patent No. 5,399,663. The industry standard is a cylindrical bushing (sometimes known as a bearing) and a cylindrical OD / tapered ID sleeve (sometimes known as a journal). The bushing has a cylindrical OD that fits tightly within the chock (bearing housing) and the sleeve has an internal taper angle that precisely matches the roll.

[0003] The '691 patent describes a typical rolling mill oil film bearing as follows: A roll 10 has a neck section 12. The neck section 12 may be conical, as shown in FIG. 1(A), or may be cylindrical in some alternative configurations. A sleeve 14 is received in and fixed relative to the neck section 12. 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 received by and fixed within a chock 22. The chock is closed at an outer end by an end plate 24 and a cover 26. A seal assembly 28 is provided between the roll and the inner end of the chock 22.

[0004] During normal operation of the mill, when the rolls are rotating at an appropriate speed for full hydrodynamic operation, a continuous flow of oil is supplied through passages 29 in the chocks, feed openings 30 in the bushings, and one of a set of rebores 32 in the bearing face 20. From here, the oil enters between the bearing face 20 and the rotating journal face 16 and flows through the bearing load zone "Z" and hydrodynamic length "L. H", i.e., a somewhat wedge-shaped oil film 34 that is hydrodynamically maintained by the length of the bushing that interacts with the sleeve to support the oil film. In FIG. 1(A) a load is applied through the roll at "SF". The load is resisted with a force "F" on the chock. The load zone is located on the same side as the resisting force "F". The pressure profile in the load zone is shown diagrammatically in FIG. 1(A) at "P".

[0005] Conventional hydrostatic means are used to create the necessary oil film between the journal and bearing surfaces when the roll is not rotating or is rotating at a speed slower than that required to create and maintain the hydrodynamic oil film 34.

[0006] Oil is continuously discharged from between the journal surface 16 and the bearing surface 20 at both the inboard and outboard ends of the load zone. Oil discharged from the inboard end enters an inner sump 36 surrounded by the seal assembly 28 and the adjacent surfaces of the chocks, bushings and rolls. Oil discharged from the outboard end enters an outer sump 38 surrounded by the end plate 24 and chocks 22. The sumps 36, 38 are interconnected by one or more passages 40 drilled through the chocks, and the outer sump 38 is connected to a conventional lubrication system (not shown) which filters, cools and recirculates the oil to the bearings for reintroduction between the bearing surface 16 and the journal surface 20.

[0007] A conventional sleeve for use on rolling mill rolls is shown at 300 in FIG. 3A. The sleeve has an inner end 301 and an outer end 302, and has (a) a hydrodynamic length L H The sleeve length L has a portion of the sleeve length that produces an oil film shown as S and diameter OD, and (b) an inner surface 304 shaped like a cone with an inner diameter ID at the inner end and a standard taper angle a. In some alternative configurations, the inner surface 304 may also alternatively be shaped like a cylinder. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Pat. No. 4,772,137 Summary of the Invention [Problem to be solved by the invention]

[0009] Embodiments of the present invention are improvements over prior art systems and methods. [Means for solving the problem]

[0010] In one embodiment, FIG. 3(B) Option 1, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S The sleeve includes a first portion of length l (i.e., a first portion of length l), the first portion having a conical shape with a first tapered portion, and (2) a second portion of length l, the second portion including (i) an undercut portion having an undercut radius r, the undercut portion located adjacent an end of the first portion proximate the inner end, and (ii) a second tapered portion located adjacent the undercut portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0011] In another embodiment, FIG. 3(B) Option 2, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the first portion having a first tapered portion, the second portion including an undercut radius r, and the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (Bearing Load Rating {F(metric tons)} / Hydrodynamic Length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0012] In yet another embodiment, FIG. 3(C) Option 1, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (LS (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the second portion including a second tapered portion adjacent to the first tapered portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0013] In another embodiment, FIG. 3(C) Option 2, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0014] In yet another embodiment, FIG. 3(B) Option 1, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , outer diameter OD, and hydrodynamic length L H and (b) providing an inner surface, the inner surface having (1) a length (L S The sleeve includes a first portion of length l (i.e., a first portion of length l), the first portion having a conical shape with a first tapered portion, and (2) a second portion of length l, the second portion including (i) an undercut portion having an undercut radius r, the undercut portion located adjacent an end of the first portion proximate the inner end, and (ii) a second tapered portion located adjacent the undercut portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0015] In another embodiment, FIG. 3(B) Option 2, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , the hydrodynamic length L Hand an outer diameter OD; and (b) providing an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the first portion having a first tapered portion, the second portion including an undercut radius r, and the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (Bearing Load Rating {F(metric tons)} / Hydrodynamic Length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0016] In yet another embodiment, FIG. 3(C) Option 1, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the second portion including a second tapered portion adjacent to the first tapered portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H(mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0017] In another embodiment, FIG. 3(C) Option 2, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) providing an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0018] The present disclosure will be described in detail with reference to the following figures, in accordance with one or more various examples. The drawings are provided for illustrative purposes only and merely illustrate examples of the present disclosure. These drawings are provided to facilitate the reader's understanding of the present disclosure and should not be considered as limiting the breadth, scope, or applicability of the present disclosure. Please note that for clarity and ease of illustration, these drawings are not necessarily made to scale. [Brief description of the drawings]

[0019] [Figure 1(A)] FIG. 1 illustrates a known hydrodynamic bearing assembly. [Figure 1(B)] FIG. 2 illustrates another view of a known hydrodynamic bearing assembly. [Diagram 2] 1A-C show the temperature distribution on the sleeve and bushing at the indicated load / speed combinations. [Figure 3(A)] FIG. 1 illustrates an embodiment of the present invention showing a standard sleeve and features added to the sleeve. [Figure 3(B)] 1A-1C show a standard sleeve and another embodiment of the present invention showing features added to the sleeve. [Figure 3(C)] FIG. 1 illustrates yet another embodiment of the present invention showing a standard sleeve and features added to the sleeve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Although the present invention has been illustrated and described in a preferred embodiment, the present invention can be manufactured in many different configurations. A preferred embodiment of the present invention is shown in the drawings and described in detail herein, with the understanding that the present disclosure should be considered as an illustration of the principles of the present invention and related functional specifications for its construction, and is not intended to limit the present invention to the illustrated embodiment. Those skilled in the art will envision many other possible variations within the scope of the present invention.

[0021] It should be noted that references herein to "one embodiment" or "an embodiment" mean that the referenced feature is included in at least one embodiment of the invention. Moreover, separate references herein to "one embodiment" do not necessarily refer to the same embodiment. However, such embodiments are not mutually exclusive unless otherwise stated and unless readily apparent to one of ordinary skill in the art. Thus, the present invention may include any various combinations and / or integrations of the embodiments described herein.

[0022] Testing of bearings under various load and speed combinations has shown that the oil film thickness on the inside of the bearing (closest to the roll face) is thinner than that on the outer end. The difference is typically between 0.05mm and 0.10mm. Because the oil film is thinner at the inner end, the shear rate of the oil film is higher, which also increases the bearing and sleeve temperatures.

[0023] Figures 2(A)-2(C) show graphs of sleeve and bushing temperature distribution at the indicated load / speed combinations (i.e., 50RPM&730T, 220RPM&650T, and 290RPM&510T, respectively). The data was obtained by testing with a full size 30"-75KL Morgoil hydrodynamic bearing. Thermocouples were installed in the bushing and sleeve. The sleeve had five thermocouples installed axially and as the sleeve rotated, the signal was output through the slip rings. The fixed bushing had four axial rows of thermocouples, two rows at + / -10 degrees and two rows at + / -45 degrees from bottom dead center. In the top diagram of Figure 2(C), the bushing thermocouple locations are indicated by white stars and the sleeve thermocouple locations are indicated by black circles.

[0024] From Figures 2(A)-2(C) it can be seen that the temperatures inside the bushing and sleeve are higher for all load / speed combinations, especially in the load zone where the film is at its minimum thickness (+ / - 10 degrees for the bushing).

[0025] Therefore, there is a need to dynamically adjust the film thickness at the inboard end of the bearing, allowing the temperature in that area to decrease as the load increases. This is important because it can reduce a major class of bearing failure called inboard edge wipe.

[0026] The prior art is replete with examples of attempting to change the shape of a bearing (stationary member) to fit the deformed shape of a shaft or housing. This invention differs in that the shape of the sleeve and bushing bearing surfaces do not change in the unloaded condition, which are cylindrical in both cases. Instead, this new concept is to add manufactured features to the sleeves to allow them to deflect as the load increases, but also to control the overall deflection. For purposes of illustration, the desired maximum radial deflection is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range 0.02≦a≦0.04, and a is preferably 0.025.

[0027] The present invention provides a feature of the length l on the tapered inside diameter (ID) of the inner end of a sleeve (e.g., a sleeve used in a rolling mill). There is a "hinge" mechanism that allows the inner end to flex inward, and the total deflection is calculated as (Bearing Load Rating {F(metric tons)} / Hydrodynamic Length {L H The offset is set by the offset on the end calculated as 0.02≦a≦0.04, where a is selected to be in the range 0.02≦a≦0.04, and a is preferably 0.025.

[0028] FIG. 3(B) shows an embodiment of the present invention. In one embodiment, FIG. 3(B) Option 1, the present invention discloses a sleeve 300 for use on a roll of a rolling mill, the sleeve having an inner end 301 and an outer end 302, the sleeve having (a) a sleeve length L S , diameter OD, hydrodynamic length L Hand outer diameter OD; and (b) inner surface 304 having an inner diameter ID at the inner end and a taper angle a, the inner surface 304 having (1) a length (L S The sleeve includes (i) a first portion of length l (310, second portion of length l) that is conical in shape with a first tapered portion 304 (which is part of the original taper that is part of the inner surface 304), and (2) a second portion of length l, the second portion of length l comprising (i) an undercut portion 312 adjacent to an end of the first portion proximate the inner end, the undercut radius r being preferably defined as 5% of l (310, second portion of length), but optionally within the range of 2% to 10%, and (ii) a second tapered portion 308 adjacent to the undercut portion that allows the sleeve to deflect as the load increases at a maximum radial deflection of δ, where l is preferably 25%*L H (hydrodynamic length), but may be within the range of 20% to 35% as necessary. The value of δ is preferably calculated by (bearing load rating {F (metric tons)} / hydrodynamic length {L H 3B, option 2, instead of taper from hinge 312 to the inner end, the overall length l is undercut by an amount δ calculated in the same manner as option 1.

[0029] In another embodiment, FIG. 3(C) Option 1, the present invention discloses a sleeve 300 for use in a rolling mill roll, the sleeve having an inner end 301 and an outer end 302, the sleeve having (a) a length L S and outer diameter OD; and (b) inner surface 304 having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S3(C) Option 2, in place of the taper of second angled portion 308, the overall length l is undercut by a constant amount δ calculated in the same manner as Option 1 above.

[0030] The bearing surface itself is cylindrical and deflects under load. The deflection can be controlled by manipulating the stiffness of the deflection characteristic. The length l is the hydrodynamic bearing length L H is a function of .

[0031] In one embodiment, FIG. 3(B) Option 1, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S The sleeve includes a first portion of length l (i.e., a first portion of length l), the first portion having a conical shape with a first tapered portion, and (2) a second portion of length l, the second portion including (i) an undercut portion having an undercut radius r, the undercut portion located adjacent an end of the first portion proximate the inner end, and (ii) a second tapered portion located adjacent the undercut portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0032] In another embodiment, FIG. 3B Option 2, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the first portion having a first tapered portion, the second portion including an undercut radius r, and the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (Bearing Load Rating {F(metric tons)} / Hydrodynamic Length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0033] In yet another embodiment, FIG. 3(C) Option 1, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L Hand an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the second portion including a second tapered portion located adjacent to the first tapered portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0034] In another embodiment, FIG. 3(C) Option 2, the present invention provides a sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end, the sleeve having (a) a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0035] In yet another embodiment, FIG. 3(B) Option 1, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , outer diameter OD, and hydrodynamic length L H and (b) providing an inner surface, the inner surface having (1) a length (L S The sleeve includes a first portion of length l (i.e., a first portion of length l), the first portion having a conical shape with a first tapered portion, and (2) a second portion of length l, the second portion including (i) an undercut portion having an undercut radius r, the undercut portion located adjacent an end of the first portion proximate the inner end, and (ii) a second tapered portion located adjacent the undercut portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0036] In another embodiment, FIG. 3(B) Option 2, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) providing an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the first portion having a first tapered portion, the second portion including an undercut radius r, and the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (Bearing Load Rating {F(metric tons)} / Hydrodynamic Length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, 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, where c is chosen to be in the range 2%≦c≦10%, and c is preferably 5%.

[0037] In yet another embodiment, FIG. 3(C) Option 1, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S(1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the second portion including a second tapered portion adjacent to the first tapered portion, the second tapered portion allowing the sleeve to deflect as the load increases at a maximum radial deflection of δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S -l) > length l.

[0038] In another embodiment, FIG. 3(C) Option 2, the present invention provides a method for reducing temperature rise inside a sleeve, the sleeve being used in a rolling mill roll, the sleeve having an inner end and an outer end, the method comprising: (a) reducing a sleeve length L S , the hydrodynamic length L H and an outer diameter OD; and (b) providing an inner surface having an inner diameter ID at an inner end and a taper angle a, the inner surface having (1) a length (L S (1) a first portion of length l, the cone-shaped first portion having a first tapered portion, and (2) a second portion of length l, the entire length l of the second portion being undercut by an amount δ. In one embodiment, δ is calculated as (bearing load rating {F(metric tons)} / hydrodynamic length {L H (mm)})*a, where a is selected to be in the range of 0.02≦a≦0.04, and a is preferably 0.025. In the same embodiment, 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%, and b is preferably 25%. In the same embodiment, the length (L S-l) > length l.

[0039] conclusion A system and method for effectively implementing bearing temperature reduction through sleeve improvements has been shown in the above embodiments. Although various preferred embodiments have been shown and described, it will be understood that no attempt is made to limit the invention by such disclosure, but rather, the intention is to cover all modifications that are within the spirit and scope of the invention as defined in the appended claims. [Explanation of symbols]

[0040] 10 roll, 12 neck section, 14 sleeve, 16 bearing surface, rotating journal surface, 18 bushing, 20 internal bearing surface, journal surface, 22 chock, 24 end plate, 26 cover, 28 seal assembly, 29 passage, 30 feed opening, 32 rebore, 34 hydrodynamic oil film, 36 inner sump, 38 outer sump, 40 passage, 300 sleeve, 301 inner end, 302 outer end, 303 outer surface, 304 inner surface, first angled portion, 308 second angled portion, 310 second portion of length, 312 undercut portion, hinge

Claims

1. 1. A sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end; The sleeve is (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and a cylindrical outer surface having an outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle a at the inner end; Equipped with The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion of length l; Equipped with The second portion is (i) an undercut portion having an undercut radius r, the undercut portion being located adjacent an end of the first portion proximate the inner end; (ii) a second sloped portion located adjacent the undercut portion, the second sloped portion tapering by an amount δ; and Equipped with The second angled portion allows the sleeve to deflect as load increases with a maximum radial deflection corresponding to the amount δ.

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

04.

3. 3. The sleeve of claim 2, wherein a is 0.

025.

4. The value of l is b * hydrodynamic length {L Ｈ 3. The sleeve of claim 2, wherein b is selected to be in the range 20%≦b≦35%.

5. 5. The sleeve of claim 4, wherein b is 25%.

6. 2. The sleeve of claim 1, wherein the undercut radius r is defined as c * length l, where c is selected to be in the range 2%≦c≦10%.

7. 7. The sleeve of claim 6, wherein c is 5%.

8. Length (L Ｓ 2. The sleeve of claim 1, wherein -l)>length l.

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

10. The sleeve of claim 9 , wherein the bushing is secured within a chock.

11. The sleeve of claim 10 , wherein an end plate and a cover are provided at the outer end to seal the bushing and the sleeve.

12. 1. A sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end; The sleeve is (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and an outer surface shaped like a cylinder having an outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle a at the inner end; Equipped with The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion of length l, the second portion including an undercut radius r, the second portion being located adjacent an end of the first portion proximate the inner end, the entire length l of the second portion being undercut by an amount δ; A sleeve comprising:

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

04.

14. 14. The sleeve of claim 13, wherein a is 0.

025.

15. The value of l is b * hydrodynamic length {L Ｈ 14. The sleeve of claim 13, wherein b is selected to be in the range 20%≦b≦35%.

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

17. 13. The sleeve of claim 12, wherein the undercut radius r is defined as c * length l, where c is selected to be in the range 2% <= c <= 10%.

18. 18. The sleeve of claim 17, wherein c is 5%.

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

20. 1. A sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end; The sleeve is (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and an outer surface shaped like a cylinder having an outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle a at the inner end; Equipped with The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion of length l, the second portion including a second sloped portion adjacent to the first sloped portion, the second sloped portion tapering by an amount δ; Equipped with the second angled portion allows the sleeve to deflect as load increases with a maximum radial deflection corresponding to the amount δ; δ is the ratio of (bearing load rating {F (metric tons)}) to hydrodynamic length {L Ｈ (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 20%≦b≦35%.

21. 21. The sleeve of claim 20, wherein a is 0.

025.

22. 22. The sleeve of claim 21, wherein b is 25%.

23. Length (L Ｓ 21. The sleeve of claim 20, wherein -l)>length l.

24. 1. A sleeve for use in a rolling mill roll, the sleeve having an inner end and an outer end; The sleeve is (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and an outer surface shaped like a cylinder having an outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle a at the inner end; Equipped with The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion having a length l, the entire length l of the second portion being undercut by an amount δ; Equipped with δ is the ratio of (bearing load rating {F (metric tons)}) to hydrodynamic length {L Ｈ (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 20%≦b≦35%.

25. 25. The sleeve of claim 24, wherein a is 0.

025.

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

27. Length (L Ｓ 25. The sleeve of claim 24, wherein -l) > length l.

28. 1. A method for reducing temperature rise inside a sleeve, the sleeve being for use with a rolling mill roll, the sleeve having an inner end and an outer end, The method comprises: (a) Sleeve length L Ｓ , outer diameter OD, and hydrodynamic length L Ｈ providing an outer surface shaped like a cylinder having a (b) providing an interior surface; Including, The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion of length l; Equipped with The second portion is (i) an undercut portion having an undercut radius r, the undercut portion being located adjacent an end of the first portion proximate the inner end; (ii) a second sloped portion located adjacent the undercut portion, the second sloped portion tapering by an amount δ; and Equipped with The second angled portion allows the sleeve to deflect as load increases with a maximum radial deflection corresponding to the amount δ.

29. δ is the product of (bearing load rating {F (metric tons)}) / hydrodynamic length {L Ｈ (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 29. The method of claim 28, wherein b is selected to be in the range 20%≦b≦35%.

30. Length (L Ｓ 29. The method of claim 28, wherein -l)>length l.

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

025.

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

33. 29. The method of claim 28, wherein the undercut radius r is defined as c * length l, where c is chosen to be in the range 2% <= c <= 10%.

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

35. 1. A method for reducing temperature rise inside a sleeve, the sleeve being for use in a rolling mill roll, the sleeve having an inner end and an outer end, The method comprises: (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and providing an outer surface shaped like a cylinder having an outer diameter OD; (b) providing an inner surface at said inner end having an inner diameter ID and a taper angle a; Including, The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion of length l, the second portion including an undercut radius r, the second portion being located adjacent an end of the first portion proximate the inner end, the entire length l of the second portion being undercut by an amount δ; A method comprising:

36. δ is the product of (bearing load rating {F (metric tons)}) / hydrodynamic length {L Ｈ (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 20%≦b≦35%.

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

025.

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

39. 37. The method of claim 36, wherein the undercut radius r is defined as c * length l, where c is chosen to be in the range 2% <= c <= 10%.

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

41. Length (L Ｓ 37. The method of claim 36, wherein -l)>length l.

42. 1. A method for reducing temperature rise inside a sleeve, the sleeve being for use in a rolling mill roll, the sleeve having an inner end and an outer end, The method comprises: (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and providing an outer surface shaped like a cylinder having an outer diameter OD; (b) an inner surface having an inner diameter ID and a taper angle a at the inner end; The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion of length l, the second portion including a second sloped portion adjacent to the first sloped portion, the second sloped portion tapering by an amount δ; Equipped with The second angled portion allows the sleeve to deflect as load increases with a maximum radial deflection corresponding to the amount δ.

43. δ is the product of (bearing load rating {F (metric tons)}) / hydrodynamic length {L Ｈ (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 43. The method of claim 42, wherein b is selected to be in the range 20%≦b≦35%.

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

025.

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

46. Length (L Ｓ 43. The method of claim 42, wherein -l) > length l.

47. 1. A method for reducing temperature rise inside a sleeve, the sleeve being for use in a rolling mill roll, the sleeve having an inner end and an outer end, The method comprises: (a) Sleeve length L Ｓ , hydrodynamic length L Ｈ and providing an outer surface shaped like a cylinder having an outer diameter OD; (b) providing an inner surface at said inner end having an inner diameter ID and a taper angle a; Including, The inner surface is (1) Length (L Ｓ -l) a first portion, said first portion being cone-shaped and having a first inclined portion; (2) a second portion having a length l, the entire length l of the second portion being undercut by an amount δ; A method comprising:

48. δ is the product of (bearing load rating {F (metric tons)}) / hydrodynamic length {L Ｈ (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 48. The method of claim 47, wherein b is selected to be in the range 20%≦b≦35%.

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

025.

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

51. Length (L Ｓ 48. The method of claim 47, wherein -l) > length l.

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