NTN Corporation (hereafter, NTN) has developed the “Self-formed Seal Low Torque Deep Groove Ball Bearing” for transmissions that is capable of reducing rotational torque by up to 80%*1 to help improve fuel efficiency and reduce CO2 emissions of automobiles.
To prevent a reduction in operating life of bearings for automotive transmissions due to the penetration of foreign objects, sealed ball bearings with contact seals are often used. Yet rotational torque is often larger than ball bearings without seals, and these bearings are often plagued with issues related to degradation due to poor lubrication.
The new “Self-formed Seal Low Torque Deep Groove Ball Bearing” employs a newly developed seal that self-forms minute gaps between the inner ring and seal. The end of the seal that comes in contact with the inner ring is a non-contact type seal that cannot be manufactured using machining or molding processes, as these seals form minute gaps during the initial stages of bearing operation. The rubber composition of the seal has been improved, and the type of contact between end of the seal and the inner ring has been changed from the conventional axial contact structure*2 to the radial contact structure*3 to ensure more reliable minute gaps are formed during the initial stages of bearing operation. These designs prevent penetration of foreign objects into the bearing that reduce its operating life, while also reducing rotational torque by up to 80% and supplying ample lubrication throughout the bearing with up to five-times the lubrication flow compared to conventional contact type bearings.
NTN will be exhibiting the newly developed product at the “Automotive Engineering Exposition 2012” to be held at Pacifico Yokohama between May 23 and 25, and plans to market the product globally as a product to help improve fuel efficiency and reduce CO2 emissions of automobiles.
|*1:||Compared to the conventional “Light Contact Seal Ball Bearing”.|
|*2:||Bearing structure where the sliding sections of seal ends are in contact with the bearing inner ring in an axial direction.|
|*3:||Bearing structure where the sliding sections of seal ends are in contact with the bearing inner ring in a radial direction.|
|(1)||Rotational torque||:||up to 80% reduction|
|(2)||Operating life||:||same or better operating life under lubrication conditions with penetration of foreign objects
(same level of foreign object penetration prevention as light contact seals)
|(3)||Lubrication||:||five-times the lubrication flow (improved anti-seizing)|
Business Planning Department, Automotive Business Headquarters