Tapered roller bearing

Patent metadata

Field	Value
Publication number	US-10288114-B2
Application number	US-201615542181-A
Country	US
Kind code	B2
Filing date	Jan 5, 2016
Priority date	Jan 28, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

A raceway surface ( 3 a ) of an outer ring ( 3 ) of a tapered roller bearing ( 1 ) includes a composite crowning surface. The composite crowning surface includes a center curve ( 3 a 1 ), which is formed at a center portion in a generating-line direction, and end portion curves ( 3 a 2 and 3 a 3 ), which are formed on both sides of the center curve ( 3 a 1 ) in the generating-line direction. The raceway surface ( 3 a ) of the outer ring ( 3 ) is entirely subjected to superfinishing. Each of a ratio (R 2 /R 1 ) of a curvature radius (R 2 ) of the end portion curve ( 3 a 2 ) to a curvature radius (R 1 ) of the center curve ( 3 a 1 ) and a ratio (R 3 /R 1 ) of a curvature radius (R 3 ) of the end portion curve ( 3 a 3 ) to the curvature radius (R 1 ) is set to 0.02 or more. Each of drop amounts of the end portion curves ( 3 a 2 and 3 a 3 ) is set to 0.07 mm or less.

First claim

The invention claimed is:

1. A tapered roller bearing, comprising:
an inner ring comprising a raceway surface having a tapered shape on an outer peripheral surface of the inner ring;
an outer ring comprising a raceway surface having a tapered shape on an inner peripheral surface of the outer ring;
a plurality of tapered rollers, which are arranged between the raceway surface of the inner ring and the raceway surface of the outer ring so as to be rollable, each of the plurality of tapered rollers comprising an outer peripheral surface having a rolling surface with a tapered shape; and
a cage which is configured to retain the plurality of tapered rollers at predetermined intervals,
wherein the raceway surface of the outer ring comprises a composite crowning surface, the composite crowning surface comprising a center curve, which is formed at a center portion in a generating-line direction and has a curvature radius R 1 , and end portion curves, which are formed on both sides of the center curve in the generating-line direction, one of the end portion curves having a curvature radius R 2 that is smaller than the curvature radius R 1 of the center curve, and another of the end portion curves having a curvature radius R 3 that is smaller than the curvature radius R 1 of the center curve,
wherein the raceway surface of the outer ring is entirely subjected to superfinishing, and
wherein each of a ratio R 2 /R 1 of the curvature radius R 2 of the one end portion curve to the curvature radius R 1 of the center curve and a ratio R 3 /R 1 of the curvature radius R 3 of the other end portion curve to the curvature radius R 1 of the center curve is set to 0.02 or more, and each of drop amounts of the end portion curves is set to 0.02 mm or more and 0.07 mm or less.

2. The tapered roller bearing according to claim 1 , wherein, under a state in which an appropriate preload in an axial direction is applied to the inner ring and the outer ring, a generating-line-direction dimension of a region of the raceway surface of the outer ring on a large-diameter side from the rolling surfaces of the plurality of tapered rollers is set to 0.6 mm or more.

3. The tapered roller bearing according to claim 1 ,
wherein the inner ring comprises a small-flange portion which is formed on a small-diameter side of the raceway surface of the inner ring, and
wherein, under a state in which an appropriate preload in an axial direction is applied to the inner ring and the outer ring, a distance between a small-diameter-side end surface of each of the plurality of tapered rollers and the small-flange portion of the inner ring is set to 0.4 mm or less.

4. The tapered roller bearing according to claim 1 , wherein the outer ring comprises a chamfered portion formed on a small-diameter-side end portion of the inner peripheral surface of the outer ring, the chamfered portion having an axial width of 0.5 mm or more.

5. The tapered roller bearing according to claim 1 , wherein the outer ring comprises a cylindrical surface formed between a chamfered portion, which is formed on a small-diameter-side end portion of the inner peripheral surface of the outer ring, and the raceway surface of the outer ring.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Kawai Takashi

Classifications

• F16C2240/50

  Crowning, e.g. crowning height or crowning radius · CPC title

• F16C2361/61

  Toothed gear systems, e.g. support of pinion shafts · CPC title

• F16C2223/02

  Mechanical treatment, e.g. finishing · CPC title

• F16C19/364 Primary

  with tapered rollers, i.e. rollers having essentially the shape of a truncated cone · CPC title

• F16C33/64

  Special methods of manufacture · CPC title