Bearing temperature reduction through bushing modification

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 LB, hydrodynamic length LH, and inner diameter ID;
• and
• (b) an outer surface (303) an outside diameter OD, the outer surface comprising:
• (1) a first portion of length (LB−), 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 δ mm, and
• wherein the second portion undercut by the constant amount δ mm allows the bushing to deflect as load increases at a maximum radial deflection of δ mm.

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 LB, a hydrodynamic length LH, 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 (LB−) 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 δ mm, and
• wherein the ramp portion (308) allows the bushing (300) to deflect as load increases at a maximum radial deflection of δ mm,
• wherein δ mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {LH in mm})*a, wherein a is picked to be in the range 0.02≤a≤0.04, wherein a value of is defined as b*Hydrodynamic Length {LH}, wherein b is picked to be within the range 20%≤b≤35%.

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 LB, a hydrodynamic length LH, 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 (LB−), 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 δ mm;
• wherein the second portion allows the bushing to deflect as load increases at a maximum radial deflection of δ mm,
• wherein, δ mm is defined as (Bearing Load Rating {F in metric tons}/Hydrodynamic Length {LH in mm})*a wherein a is picked to be in the range 0.02≤a≤0.04, and wherein a value of is defined as b*Hydrodynamic Length {LH}, wherein b is picked to be within the range 20%≤b≤35%.

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 LB, inner diameter ID, and hydrodynamic length LH;
• and
• (b) provisioning an outer surface (303) comprising:
• (1) a first portion of length (LB−), 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 δ mm, and
• wherein the ramp portion (308) allows the bushing (300) to deflect as load increases at a maximum radial deflection of δ mm.

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 LB, hydrodynamic length LH, 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 (LB−), 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 δ mm, and
• wherein the second portion undercut by the constant amount δ mm allows the bushing to deflect as load increases at a maximum radial deflection of δ mm.

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 LB, hydrodynamic length LH, 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 (LB−), 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 δ mm, and wherein the ramp portion (308) allows the bushing to deflect as load increases at a maximum radial deflection of δ mm.

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 LB, a hydrodynamic length LH, 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 (LB−), 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 δ mm, wherein the second portion allows the bushing to deflect as load increases at a maximum radial deflection of δ mm.