US 12,110,925 B2
Roller bearing
Tomonori Suwa, Fujisawa (JP); Kentaro Oguma, Fujisawa (JP); and Yoshinori Maeda, Fujisawa (JP)
Assigned to NSK LTD., Tokyo (JP)
Appl. No. 17/796,079
Filed by NSK LTD., Tokyo (JP)
PCT Filed Jan. 29, 2021, PCT No. PCT/JP2021/003434
§ 371(c)(1), (2) Date Jul. 28, 2022,
PCT Pub. No. WO2021/153793, PCT Pub. Date Aug. 5, 2021.
Claims priority of application No. 2020-014135 (JP), filed on Jan. 30, 2020.
Prior Publication US 2023/0084172 A1, Mar. 16, 2023
Int. Cl. F16C 33/58 (2006.01); F16C 19/26 (2006.01); F16C 19/36 (2006.01); F16C 33/36 (2006.01)
CPC F16C 33/585 (2013.01) [F16C 19/26 (2013.01); F16C 19/364 (2013.01); F16C 33/366 (2013.01); F16C 2240/50 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A roller bearing comprising:
an outer ring having an outer ring raceway surface on an inner peripheral surface;
an inner ring having an inner ring raceway surface on an outer peripheral surface; and
a plurality of rollers rotatably arranged between the outer ring raceway surface and the inner ring raceway surface and having rolling surfaces on outer peripheral surfaces, wherein
crowning is applied to at least one of the outer ring raceway surface, the inner ring raceway surface, and the rolling surface, and
a generatrix shape to which the crowning is applied includes,
a first generatrix shape which is formed in a central portion in an axial direction of at least one of the outer ring raceway surface, the inner ring raceway surface, and the rolling surface of the roller and is composed of a straight line,
a pair of second generatrix shapes which are formed from both ends in the axial direction toward the outside in the axial direction of the first generatrix shape and are composed of a single arc curve, and
a pair of third generatrix shapes which are formed from both ends in the axial direction toward the outside in the axial direction of the second generatrix shape and are composed of a composite curve of a single arc curve and a logarithmic curve, wherein
when a center of the first generatrix shape in the axial direction is set to an origin 0, an amount of displacement from the origin 0 to the outside in the axial direction is set to X, and a crowning drop amount of the crowning is set to δ,
La is set as an axial length from the origin 0 of the first generatrix shape,
Lb is set as an axial length of the second generatrix shape,
Le is set as an effective contact length between the rolling surface of the roller and the inner ring raceway surface or the outer ring raceway surface,
R is set as an arc radius of the single arc curve of the second generatrix shape,
Q is set as a contact load between the rolling surface of the roller and the inner ring raceway surface or the outer ring raceway surface,
ν1 and ν2 are set as a Poisson's ratio of the rolling surface of the roller and the inner ring raceway surface or the outer ring raceway surface,
E1 and E2 are set as a Young's modulus of the rolling surface of the roller and the inner ring raceway surface or the outer ring raceway surface, and
b is set as ½ of a contact width of Hertz,
the crowning drop amount δ in the first generatrix shape is defined by a formula of
0≤X≤La
δ=0,  [Equation 1]
the crowning drop amount δ in the second generatrix shape is defined by a formula of
La<X≤La+Lb
δ=R−√R2−(X−La)2, and  [Equation 2]
the crowning drop amount δ in the third generatrix shape is defined by a formula of

OG Complex Work Unit Math