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The configuration of the TDO provides a wide effective bearing spread, making it ideal for applications in which overturning moments are a significant load component. TDO bearings can be used in fixed positions or allowed to float in the housing bore.
Unit of Measure

Specifications

Series

N/A M270700

Cone Part Number

N/A M270749A

Cup Part Number

N/A M270710CD

Design Unit

N/A Inch

Cage Material

N/A Stamped Steel

Related Assembly Number(s)

N/A M270749A-902B4 M270749A-902B5

Dimensions

d - Bore

N/A 17.6250 in447.675 mm

D - Cup Outer Diameter

N/A 25.0000 in635 mm

B - Cone Width

N/A 4.7500 in120.650 mm

C - Double Cup Width

N/A 8.1250 in206.375 mm

T - Bearing Width across Cones

N/A 10.1250 in257.175 mm

Abutment and Fillet Dimensions

R - Cone Backface "To Clear" Radius1 N/A 0.25 in6.4 mm
r - Cup Backface "To Clear" Radius2 N/A 0.06 in1.5 mm

db - Cone Backface Backing Diameter

N/A 19.06 in484 mm

Da - Cup Frontface Backing Diameter

N/A 23.98 in605.03 mm

Aa - Cage-Cone Backface Clearance

N/A 0.37 in9.4 mm
a - Effective Center Location3 N/A -0.32 in-8.1 mm

Basic Load Ratings

C90 - Dynamic Radial Rating (One-Row, 90 million revolutions)4 N/A 799000 N
C1 - Dynamic Radial Rating (Two-Row, 1 million revolutions)5 N/A 1210000 lbf5370000 N
C90(2) - Dynamic Radial Rating (Two-Row, 90 million revolutions)6 N/A 313000 lbf1390000 N
Ca90 - Dynamic Thrust Rating (90 million revolutions)7 N/A 102000 lbf455000 N

Factors

K - Factor8 N/A 1.76
e - ISO Factor9 N/A 0.33
Y1 - ISO Factor10 N/A 2.03
Y2 - ISO Factor11 N/A 3.02
Cg - Geometry Factor12 N/A 0.241
  • 1 These maximum fillet radii will be cleared by the bearing corners.
  • 2 These maximum fillet radii will be cleared by the bearing corners.
  • 3 Negative value indicates effective center inside cone backface.
  • 4 Based on 90 x 106 revolutions L10 life, for The Timken Company life calculation method. C90 and Ca90 are radial and thrust values.
  • 5 Based on 1 x 106 revolutions L10 life, for the ISO life calculation method.
  • 6 Based on 90 x 106 revolutions L10 life, for The Timken Company life calculation method. C90 and Ca90 are radial and thrust values for a single-row, C90(2) is the two-row radial value.
  • 7 Based on 90 x 106 revolutions L10 life, for The Timken Company life calculation method. C90 and Ca90 are radial and thrust values for a single-row, C90(2) is the two-row radial value.
  • 8 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 9 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 10 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 11 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 12 Geometry constant for Lubrication Life Adjustment Factor a3l.