Tapered roller bearing

• US 9,816,557 B2
• Filed: 06/05/2014
• Issued: 11/14/2017
• Est. Priority Date: 06/10/2013
• Status: Active Grant

• Current Assignee: NTN Corporation
• Original Assignee: NTN Corporation
• Inventors: Ueno, Takashi
• Primary Examiner(s): Charles, Marcus
• Application Number:
  US14/896,886
• Publication Number:
  US 20160153495A1
• Time in Patent Office: 1,258 Days
• Field of Search: 384450, 384470, 384571-572, 384575, 384593, 384564, 384569, 29898067, 2989807
• CPC Class Codes: C21D 9/36 for balls; for rollers
• CPC Class Codes: C21D 9/40 for rings; for bearing races
• CPC Class Codes: C22C 38/00 Ferrous alloys, e.g. steel alloys cast-iron alloys C22C37/00
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/12 containing tungsten, tantalum, molybdenum, vanadium, or niobium
• CPC Class Codes: C22C 38/18 containing chromium
• CPC Class Codes: C22C 38/34 with more than 1.5% by weight of silicon
• CPC Class Codes: C22C 38/40 with nickel
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C23C 8/32 of ferrous surfaces
• CPC Class Codes: F16C 19/364 with tapered rollers, i.e. rollers having essentially the shape of a truncated cone
• CPC Class Codes: F16C 19/542 with two rolling bearings with angular contact
• CPC Class Codes: F16C 19/547 with two angular contact rolling bearings
• CPC Class Codes: F16C 2204/64 Medium carbon steel, i.e. carbon content from 0.4 to 0,8 wt%
• CPC Class Codes: F16C 2204/66 High carbon steel, i.e. carbon content above 0.8 wt%, e.g. through-hardenable steel
• CPC Class Codes: F16C 2204/74 with manganese as the next major constituent
• CPC Class Codes: F16C 2361/61 Toothed gear systems, e.g. support of pinion shafts in general F16H57/02
• CPC Class Codes: F16C 33/56 : Selection of substances F16C33/48, F16C33/49 take precedence
• CPC Class Codes: F16C 33/62 : Selection of substances

Abstract

A tapered roller bearing includes an outer ring, an inner ring, a plurality of tapered rollers, and a holder. A nitrogen concentration in a surface layer portion under a contact surface is 0.3 mass % or more. The holder includes a small annular portion, a large annular portion, and a plurality of column portions. A pocket has a trapezoidal shape in which a portion housing a small diameter side of the tapered roller is located on a reduced width side while a portion housing a large diameter side of the tapered roller is located on an increased width side. Each of the column portions on the reduced width side of the pocket is provided with a cutout.

Claims

1. A tapered roller bearing comprising:

an outer ring having an outer ring rolling contact surface on an inner circumferential surface;

an inner ring having an inner ring rolling contact surface on an outer circumferential surface, having a small collar and a large collar formed on both sides of said inner ring rolling contact surface, and arranged on an inner side of said outer ring;

a plurality of tapered rollers arranged between said outer ring rolling contact surface and said inner ring rolling contact surface; and

a holder having a pocket housing each of said tapered rollers,

at least one of bearing components including said outer ring, said inner ring and said tapered roller being made of steel consisting of 0.6 mass % or more and 1.50 mass % or less of carbon, 0.15 mass % or more and 2.50 mass % or less of silicon, 0.30 mass % or more and 1.50 mass % or less of manganese, and 0.20 mass % or more and 2.00 mass % or less of chromium, with the rest made up of iron, unavoidable impurities, and a nitrogen concentration in a surface layer portion under a contact surface in contact with another component being 0.3 mass % or more,

said holder including a small annular portion continuously extending on a side of a small diameter end face of said tapered roller, a large annular portion continuously extending on a side of a large diameter end face of said tapered roller, and a plurality of column portions coupling said small annular portion and said large annular portion,

said pocket having a trapezoidal shape in which a portion housing a small diameter side of said tapered roller is located on a reduced width side while a portion housing a large diameter side of said tapered roller is located on an increased width side, and

each of said column portions on said reduced width side of said pocket being provided with a cutout.

2. The tapered roller bearing according to claim 1, wherein

said large collar includes a large collar surface that is in sliding contact with said large diameter end face of said tapered roller, and

the nitrogen concentration in each of said surface layer portion under said large diameter end face and said surface layer portion under said large collar surface is 0.3 mass % or more.

3. The tapered roller bearing according to claim 1, wherein

in at least one of the bearing components including said outer ring, said inner ring and said tapered roller, said surface layer portion under said contact surface includes five or more carbonitrides each having a diameter of 0.5 μ

m or less that are present per 100 μ

2 in a cross section perpendicular to said contact surface.

4. The tapered roller bearing according to claim 1, wherein

in at least one of the bearing components including said outer ring, said inner ring and said tapered roller, a retained austenite amount in a region extending from said contact surface to a depth of 50 μ

m is 20 vol % or more.

5. The tapered roller bearing according to claim 1, wherein

a nitrogen concentration in an inner diameter surface of said inner ring is 0.05 mass % or less.

6. The tapered roller bearing according to claim 1, wherein

said tapered roller bearing supports a rotation member, which rotates within a differential or a transmission, so as to be rotatable relative to another member arranged adjacent to said rotation member.

7. The tapered roller bearing according to claim 1, wherein

a small annular portion on the reduced width side of said pocket is provided with a cutout.

8. The tapered roller bearing according to claim 1, wherein

each said column portion on the increased width side of said pocket is provided with a cutout.

9. The tapered roller bearing according to claim 8, wherein

a total area of the cutout provided in each said column portion on the reduced width side of said pocket is greater than a total area of said cutout provided in each said column portion on said increased width side of said pocket.

10. The tapered roller bearing according to claim 1, wherein the small annular portion of said holder is provided with a collar facing said small collar of said inner ring, and

a gap between said collar of said small annular portion and said small collar of said inner ring is 2.0% or less of an outer diameter of said small collar of said inner ring.

11. The tapered roller bearing according to claim 1, wherein said tapered roller has a surface provided with a recess formed in a concave shape, and

said surface of said tapered roller has a surface roughness (Ryni) of 0.4 μ

m or more and 1.0 μ

m or less, and an Sk value of −

1.6 or less.

12. A tapered roller bearing comprising:

an outer ring having an outer ring rolling contact surface on an inner circumferential surface;

an inner ring having an inner ring rolling contact surface on an outer circumferential surface, having a small collar and a large collar formed on both sides of said inner ring rolling contact surface, and arranged on an inner side of said outer ring;

a plurality of tapered rollers arranged between said outer ring rolling contact surface and said inner ring rolling contact surface; and

a holder having a pocket housing each of said tapered rollers,

at least one of bearing components including said outer ring, said inner ring and said tapered roller being made of steel containing 0.6 mass % or more and 1.50 mass % or less of carbon, 0.15 mass % or more and 2.50 mass % or less of silicon, 0.30 mass % or more and 1.50 mass % or less of manganese, and 0.20 mass % or more and 2.00 mass % or less of chromium, and further containing at least one of 0.5 mass % or less of nickel and 0.2 mass % or less of molybdenum, with the rest made up of iron, unavoidable impurities, and a nitrogen concentration in a surface layer portion under a contact surface in contact with another component being 0.3 mass % or more,

said holder including a small annular portion continuously extending on a side of a small diameter end face of said tapered roller, a large annular portion continuously extending on a side of a large diameter end face of said tapered roller, and a plurality of column portions coupling said small annular portion and said large annular portion,

said pocket having a trapezoidal shape in which a portion housing a small diameter side of said tapered roller is located on a reduced width side while a portion housing a large diameter side of said tapered roller is located on an increased width side,

each of said column portions on said reduced width side of said pocket being provided with a cutout,

at least one of the bearing components including said outer ring, said inner ring, and said tapered roller has an entire average retained austenite amount of 20 vol % or less.

13. A tapered roller bearing comprising:

an outer ring having an outer ring rolling contact surface on an inner circumferential surface;

an inner ring having an inner ring rolling contact surface on an outer circumferential surface, having a small collar and a large collar formed on both sides of said inner ring rolling contact surface, and arranged on an inner side of said outer ring;

a plurality of tapered rollers arranged between said outer ring rolling contact surface and said inner ring rolling contact surface; and

a holder having a pocket housing each of said tapered rollers,

at least said tapered roller among said outer ring, said inner ring and said tapered roller being made of quench-hardened steel containing 0.90 mass % or more and 1.05 mass % or less of carbon, 0.15 mass % or more and 0.35 mass % or less of silicon, 0.01 mass % or more and 0.50 mass % or less of manganese, and 1.30 mass % or more and 1.65 mass % or less of chromium, with the rest made up of iron, unavoidable impurities, and a nitrogen concentration in a contact surface that is in contact with another component being 0.25 mass % or more, wherein a retained austenite amount in said contact surface is 6 vol % or more and 12 vol % or less.

14. The tapered roller bearing according to claim 13, wherein

said holder includes a small annular portion continuously extending on a side of a small diameter end face of said tapered roller, a large annular portion continuously extending on a side of a large diameter end face of said tapered roller, and a plurality of column portions coupling said small annular portion and said large annular portion,

said pocket has a trapezoidal shape in which a portion housing a small diameter side of said tapered roller is located on a reduced width side while a portion housing a large diameter side of said tapered roller is located on an increased width side, and

each of said column portions on said reduced width side of said pocket is provided with a cutout.

15. The tapered roller bearing according to claim 13, wherein

said contact surface of at least said tapered roller among said outer ring, said inner ring and said tapered roller has a hardness of 60.0 HRC or more.

16. The tapered roller bearing according to claim 13, wherein

said contact surface of at least said tapered roller among said outer ring, said inner ring and said tapered roller has a hardness of 64.0 HRC or less.