BEARING TEMPERATURE REDUCTION THROUGH BUSHING MODIFICATION

Abstract

A novel bushing (300) is disclosed as used in a bearing in a rolling mill, where a feature of length l is introduced on the inboard portion (301) of an outer surface (303) of the bushing (300), where the introduced feature allows the bushing (300) to deflect as load increases at a maximum radial deflection of mm. The introduced feature deals with elevated temperatures on the inboard side of the bushing (300) by allowing the bushing to deflect as the load increases.

Claims

1. A bushing (300) for use in a bearing of a rolling mill, the bushing (300) having an inboard end (301) and an outboard end (302), the bushing (300) comprising: (a) an inner surface (304) shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inside diameter ID; and (b) an outer surface (303) having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, the second portion comprises: (i) an undercut portion (312) having an undercut radius, r, the undercut portion located adjacent to an end of the first portion that is proximate to the inboard end; (ii) a ramp portion (308) located adjacent to the undercut portion (312), the ramp portion (308) provided with a tapered portion from the undercut portion (312) having radius r to the inboard end (301), the tapered portion tapered by an amount mm, and wherein the ramp portion (308) allows the bushing (300) to deflect as load increases at a maximum radial deflection of mm.

2. The bushing (300) of claim 1, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04.

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3. The bushing (300) of claim 1, wherein a sleeve is disposed around the inner surface of the bushing (300), wherein a gap exists between the bushing (300) and the outer surface of the sleeve, the gap configured to maintain a hydrodynamically-maintained oil film.

4. The bushing (300) of claim 3, wherein the bushing (300) is fixed within a chock.

5. The bushing (300) of claim 4, wherein an end plate and a cover are provided at the outboard end (302) to seal the bushing (300) and the sleeve.

6. A bushing (300) for use in a bearing of a rolling mill, the bushing (300) having an inboard end (301) and an outboard end (302), the bushing comprising: (a) an inner surface (304) shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inner diameter ID; and (b) an outer surface (303) an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, the second portion comprises an undercut portion (312) having an undercut radius, r, wherein a full length of the second portion is undercut by a constant amount mm, and wherein the second portion undercut by the constant amount mm allows the bushing to deflect as load increases at a maximum radial deflection of mm.

7. The bushing (300) of claim 6, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04.

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8. A bearing comprising a bushing (300) for use in a rolling mill, the bushing (300) having an inboard end (301) and an outboard end (302), the bushing (300) comprising: (a) an inner surface (304) shaped like a cylinder having bushing length L.sub.B, a hydrodynamic length L.sub.H, and inside diameter ID; (b) an outer surface (303) having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B) the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, the second portion comprising a ramp portion (308) located adjacent to the first portion, the ramp portion (308) provided with a tapered portion from the first portion to the inboard end (301), the tapered portion by an amount mm, and wherein the ramp portion (308) allows the bushing (300) to deflect as load increases at a maximum radial deflection of mm, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a, wherein a is picked to be in the range 0.02a0.04, wherein a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35%.

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9. A bearing comprising a bushing (300) for use in a rolling mill, the bushing having an inboard end (301) and an outboard end (302), the bushing (300) comprising: (a) an inner surface (304) shaped like a cylinder having bushing length L.sub.B, a hydrodynamic length L.sub.H, and inside diameter ID; (b) an outer surface (303) having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, a full length (310) of the second portion is undercut by a constant amount mm; wherein the second portion allows the bushing to deflect as load increases at a maximum radial deflection of mm, wherein, mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04, and wherein a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35%.

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10. A method for lowering temperature build-up on an inboard side of a bushing (300), the bushing (300) for use in a bearing of a rolling mill, the bushing (300) having an inboard end (301) and an outboard end (302), the method comprising: (a) provisioning an inner surface (304) shaped like a cylinder having bushing length L.sub.B, inner diameter ID, and hydrodynamic length L.sub.H; and (b) provisioning an outer surface (303) comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , the second portion comprising: (i) an undercut portion (312) having an undercut radius, r, the undercut portion located adjacent to an end of the first portion that is proximate to the inboard end; (ii) a ramp portion (308) located adjacent to the undercut portion (312), characterized in that, the ramp portion (308) is provided with a tapered portion from the undercut portion (312) having radius r to the inboard end (301), the tapered portion tapered by an amount mm, and wherein the ramp portion (308) allows the bushing (300) to deflect as load increases at a maximum radial deflection of mm.

11. The method of claim 10, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a, wherein a is picked to be in the range 0.02a0.04, and a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35%.

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12. A method for lowering temperature build-up on an inboard side of a bushing (300), the bushing (300) for use in a bearing of a rolling mill, the bushing (300) having an inboard end (301) and an outboard end (302), the method comprising: (a) provisioning an inner surface (304) shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inside diameter ID; and (b) provisioning an outer surface (303) having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, the second portion comprises an undercut portion (312) having an undercut radius, r, wherein a full length of the second portion is undercut by a constant amount mm, and wherein the second portion undercut by the constant amount mm allows the bushing to deflect as load increases at a maximum radial deflection of mm.

13. The method of claim 12, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04, and wherein a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35%.

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14. A method for lowering temperature build-up on an inboard side of a bushing (300), the bushing (300) for use in a bearing of a rolling mill, the bushing having an inboard end (301) and an outboard end (302), the method comprising: (a) provisioning an inner surface (304) shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inside diameter ID; (b) an outer surface (303) having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, the second portion comprises a ramp portion (308) located adjacent to the first portion, the ramp portion (308) provided with a tapered portion from the first portion to the inboard end (301), the tapered portion tapered by an amount mm, and wherein the ramp portion (308) allows the bushing to deflect as load increases at a maximum radial deflection of mm.

15. The method of claim 14, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04, and a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35%.

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16. A method for lowering temperature build-up on an inboard side of a bushing (300), the bushing (300) for use in a bearing of a rolling mill, the bushing (300) having an inboard end and an outboard end, the method comprising: (a) provisioning an inner surface (304) shaped like a cylinder having bushing length L.sub.B, a hydrodynamic length L.sub.H, and inside diameter ID; (b) provisioning an outer surface (303) having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length (310), characterized in that, a full length of the second portion is undercut by a constant amount mm, wherein the second portion allows the bushing to deflect as load increases at a maximum radial deflection of mm.

17. The method of claim 16, wherein mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04, and a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35%.

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Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present disclosure, in accordance with one or more various examples, is described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict examples of the disclosure. These drawings are provided to facilitate the reader's understanding of the disclosure and should not be considered limiting of the breadth, scope, or applicability of the disclosure. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.

[0018] FIGS. 1(A)-(B) depict a known hydrodynamic bearing assembly.

[0019] FIGS. 2(A)-(C) depict temperature distribution on the sleeve and bushing at the indicated load/speed combinations.

[0020] FIGS. 3(A)-(C) depict a standard bushing and then illustrate several embodiments of the present invention depicting features that are added to the bushing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] While this invention is illustrated and described in a preferred embodiment, the invention may be produced in many different configurations. There is depicted in the drawings, and will herein be described in detail, a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the invention to the embodiment illustrated. Those skilled in the art will envision many other possible variations within the scope of the present invention.

[0022] Note that in this description, references to one embodiment or an embodiment mean that the feature being referred to is included in at least one embodiment of the invention. Further, separate references to one embodiment in this description do not necessarily refer to the same embodiment; however, neither are such embodiments mutually exclusive, unless so stated and except as will be readily apparent to those of ordinary skill in the art. Thus, the present invention can include any variety of combinations and/or integrations of the embodiments described herein.

[0023] Testing of the bearing under various load and speed combinations has shown that the oil film thickness at the inboard side of the bearing (side nearest the roll face) is thinner than that at the outboard end. The difference is typically between 0.05 mm and 0.10 mm. Since the oil film is thinner on the inboard end, the shear rate in the oil film is higher, and the bushing and sleeve temperature are also increased.

[0024] FIGS. 2(A) through 2(C) show graphs of temperature distribution in the sleeve and bushing at the indicated load/speed combinations (i.e., at 50 RPM & 730 tons, 220 RPM & 650 tons, and 290 RPM & 510 tons, respectively). This data was obtained through testing with a full-size 30-75 KL Morgoil hydrodynamic bearing.

[0025] Thermocouples were installed in the bushing and sleeve. The sleeve had five thermocouples installed in an axial line and since the sleeve rotates the signal was brought out through a slip ring. The fixed bushing has four axial rows of four thermocouples, two rows at +/10 degrees and two rows at +/45 degrees from bottom dead center. In the diagram at the top of FIG. 2(C), the bushing thermocouple locations are denoted by a white star and the sleeve thermocouple locations are denoted by a black circle.

[0026] It can be seen from FIGS. 2(A) through 2(C) that the temperature at the inboard side of the bushing and sleeve is higher for all load/speed combinations, particularly in the load zone (+/10 degrees in the bushing) where the film is at its minimum thickness.

[0027] Therefore, there is a need to dynamically adjust the film thickness on the inboard end of the bearing, so as the load increases it would be possible to reduce the temperature in that region. This is important as it could reduce a major class of bearing failure called inboard edge wipe.

[0028] Prior art is replete with examples that attempt to change the shape of the bearing (static member) to conform to the deformed shape of a shaft or housing. The present invention is different in that the shape of the sleeve and bushing bearing surfaces are not changed in the unloaded conditionin both cases they are cylindrical. Instead, this new concept is to add manufactured features to the bushing to allow them to deflect as the load increases, but to also control the total deflection. For the purpose of explanation, the desired maximum radial deflection will be calculated as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025.

[0029] The present invention provides a feature of length on the outer diameter (OD) of the inboard end of a bushing (e.g., a bushing used in a rolling mill). There is a hinge feature to allow that inboard end to deflect outward and that total deflection is set by the offset on the end calculated as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025.

[0030] FIG. 3(B) depicts an implementation of the present invention. In one embodiment, FIG. 3(B) option 1, the present invention discloses a bushing 300 as used on a bearing in a rolling mill, the bushing having an inboard end 301 and an outboard end 302, the bushing comprising: (a) an inner surface 304 shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H and inside diameter ID; (b) an outer surface 303 comprised of an outside diameter OD: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped having a first portion 303 (which is a portion of the original outer surface 303); and (2) a second portion of length , the second portion comprising: (i) an undercut portion 312 located adjacent to an end of the first portion that is proximate to the inboard end, where r, the undercut radius, is preferable defined as 5% of (310 the second portion of length) but optionally can be within the range 2% to 10%; (ii) a second ramp portion 308 located adjacent to the undercut portion, wherein the second ramp portion allows the bushing to deflect as load increases at a maximum radial deflection of . Where is preferably defined as 25%*L.sub.H (hydrodynamic length), but optionally can be within the range 20% to 35%. Also, the value for can be preferably calculated as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. Alternately, in FIG. 3(B) option 2, instead of a taper from the hinge 312 to the inboard end, the full length is undercut by a constant amount calculated in the same manner as option 1.

[0031] In another embodiment, FIG. 3(C) option 1, the present invention discloses a bushing 300 as used on a bearing in a rolling mill, the bushing having an inboard end 301 and an outboard end 302, the bushing comprising: (a) an inner surface 304 shaped like a cylinder having length L.sub.B and diameter ID; (b) an outer surface 303 having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped having a first portion 303; and (2) a second portion of length , the second portion comprising a ramp portion 308 located adjacent to the first ramp portion 303, wherein the second ramp portion allows the bushing to deflect as load increases at a maximum radial deflection of . Alternately, in FIG. 3(C) option 2, instead of a taper on the second ramp portion 308, the full length is undercut by a constant amount calculated in the same manner as option 1, above.

[0032] The bearing surfaces themselves are cylindrical and deflect under load. That deflection is controllable through manipulating stiffness of the deflection feature. The length is a function of the hydrodynamic bearing length L.sub.H.

[0033] In one embodiment, FIG. 3(B) option 1, the present invention provides a bushing as used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the bushing comprising: (a) an inner surface shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inside diameter ID, and (b) an outer surface having an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion conically shaped having a first portion; and (2) a second portion of length , the second portion comprising: (i) an undercut portion having an undercut radius, r, the undercut portion located adjacent to an end of the first portion that is proximate to the inboard end; (ii) a ramp portion located adjacent to the undercut portion, and wherein the ramp portion allows the bushing to deflect as load increases at a maximum radial deflection of . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length . In the same embodiment, the undercut radius r is defined as c*length wherein c, is picked to be in the range 2%c10% with c preferable 5%.

[0034] In another embodiment, FIG. 3(B) option 2, the present invention provides a bushing as used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the bushing comprising: (a) an inner surface shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H and inside diameter ID; and (b) an outer surface having an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , wherein the second portion comprises an undercut radius, r, wherein a full length of the second portion is undercut by a constant amount . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length . In the same embodiment, the undercut radius r is defined as c*length wherein c, is picked to be in the range 2%c10% with c preferable 5%.

[0035] In yet another embodiment, FIG. 3(C) option 1, the present invention provides a bushing as used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the bushing comprising: (a) an inner surface shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inside diameter ID; (b) an outer surface having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , the second portion comprising a ramp portion located adjacent to the first portion, wherein the second ramp portion allows the bushing to deflect as load increases at a maximum radial deflection of . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length .

[0036] In another embodiment, FIG. 3(C) option 2, the present invention provides a bushing as used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the bushing comprising: (a) an inner surface shaped like a cylinder having bushing length L.sub.B, a hydrodynamic length L.sub.H, and inside diameter ID; (b) an outer surface having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , wherein a full length of the second portion is undercut by a constant amount . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length .

[0037] In yet another embodiment, FIG. 3(B) option 1, the present invention provides a method for lowering temperature build-up on an inboard side of a bushing, the bushing used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the method comprising: (a) provisioning an inner surface shaped like a cylinder having bushing length L.sub.B, inner diameter ID, and hydrodynamic length L.sub.H; and (b) provisioning an outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , the second portion comprising: (i) an undercut portion having an undercut radius, r, the undercut portion located adjacent to an end of the first portion that is proximate to the inboard end; (ii) a ramp portion located adjacent to the undercut portion, and wherein the ramp portion allows the bushing to deflect as load increases at a maximum radial deflection of . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a, is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length . In the same embodiment, the undercut radius, r, is defined as c*length wherein c, is picked to be in the range 2%c10% with c preferable 5%.

[0038] In another embodiment, FIG. 3(B) option 2, the present invention provides a method for lowering temperature build-up on an inboard side of a bushing, the bushing used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the method comprising: (a) provisioning an inner surface shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H and inside diameter ID; and (b) provisioning an outer surface having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , wherein the second portion comprises an undercut radius, r, wherein a full length of the second portion is undercut by a constant amount . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length . In the same embodiment, the undercut radius r is defined as c*length wherein c, is picked to be in the range 2%c10% with c preferable 5%.

[0039] In yet another embodiment, FIG. 3(C) option 1, the present invention provides a method for lowering temperature build-up on an inboard side of a bushing, the bushing used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the method comprising: (a) an inner surface shaped like a cylinder having bushing length L.sub.B, hydrodynamic length L.sub.H, and inside diameter ID; (b) an outer surface having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , the second portion comprising a ramp portion located adjacent to the first portion, wherein the second ramp portion allows the bushing to deflect as load increases at a maximum radial deflection of . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length .

[0040] In another embodiment, FIG. 3(C) option 2, the present invention provides a method for lowering temperature build-up on an inboard side of a bushing, the bushing used in a bearing in a rolling mill, the bushing having an inboard end and an outboard end, the method comprising: (a) provisioning an inner surface shaped like a cylinder having bushing length L.sub.B, a hydrodynamic length L.sub.H, and inside diameter ID; (b) provisioning an outer surface having of an outside diameter OD, the outer surface comprising: (1) a first portion of length (L.sub.B), the first portion cylindrically shaped; and (2) a second portion of length , wherein a full length of the second portion is undercut by a constant amount . In one embodiment, is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {L.sub.H in mm})*a wherein a is picked to be in the range 0.02a0.04 with a preferable 0.025. In the same embodiment, a value of l is defined as b*Hydrodynamic Length {L.sub.H}, wherein b is picked to be within the range 20%b35% with b preferable 25%. In the same embodiment, length (L.sub.B)>length .

CONCLUSION

[0041] A system and method have been shown in the above embodiments for the effective implementation of a bearing temperature reduction through bushing modification. While various preferred embodiments have been shown and described, it will be understood that there is no intent to limit the invention by such disclosure, but rather, it is intended to cover all modifications falling within the spirit and scope of the invention, as defined in the appended claims.