Development of “Enhanced Anti-indentation Deep Groove Ball Bearing”

[Replacement for tapered roller bearings and lower fuel consumption by improving static load capacity of ball bearings!]

NTN Corporation (hereafter, NTN) has developed the “Enhanced Anti-indentation Deep Groove Ball Bearing” with a higher static strength across the bearing raceway surface that can be used in automotive differentials^*1 (hereafter, diffs) and transmissions.

Further lower level of torque and higher efficiency are required of bearings as there is a greater need for fuel efficiency in automobile and reduction of CO₂ emissions. Bearings used in drivetrain components such as diffs and transmissions are subjected to large thrust loads. Accordingly tapered roller bearings are widely used in these applications, however tapered roller bearings suffer from issues such as a relatively high rotational torque and the need to adjust preload during assembly. In contrast, ball bearings have a low torque and are capable of supporting thrust, however there were no ball bearings available to meet the thrust load capacities required for such applications.

The newly developed “Enhanced Anti-indentation Deep Groove Ball Bearing” features special surface modification during the heat treatment process, which has reduced the Brinell Indentation^*2 depth - an index for static load capacity - to 1/2 compared to that of standard heat treatment. This allows tapered roller bearings used in diffs and other applications to be replaced with ball bearings, with an approximately 60%^*3 reduction in torque expected in diff side bearings. The number of man-hours required for assembly and preload control process can also be reduced, contributing to improvement in productivity at automotive manufacturers, in addition to fuel efficiency in automobile.

*1:	A drivetrain component used in vehicles with wheels such as automobiles. A differential compensates for the difference in wheel speeds (difference in speed between the inside and outside wheel) when an automobile turns a corner, and ensures that torque is distributed evenly from the power unit.
*2:	Plastic deformation indentation left in objects after removing forces that exceed the plastic limit of the material when two objects are in Hertzian contact
*3:	Compared with tapered roller bearings used in diffs for 2-liter class models, with 70% engine torque load and driving at 100 km/h

[ Features ]

(1)	Static load capacity	:	1/2 the Brinell Indentation depth compared to standard heat treatment
(2)	Bearing torque	:	60% reduction compared to tapered rolling bearings
(3)	Reduced assembly man-hours	:	preload adjustments not required during transmission assembly

[ Inquiries about this release ]

[ Product photo ]

“Enhanced Anti-indentation Deep Groove Ball Bearing”
Bearing dimensions φ30 × φ63 × 16

[ Applicable areas ]

Example of differential	Example of CVT
Automobile drivetrain components