HOME > Product and Technology > New Products : 2017 >  Development of “Ultra-low Friction Sealed Ball Bearing” for automotive transmissions

2017

Print

New Product
Development of “Ultra-low Friction Sealed Ball Bearing” for automotive transmissions
June 5, 2017New Products

Achieves a low torque equivalent to non-contact sealed type

NTN Corporation (hereafter, NTN) has developed the “Ultra-low Friction Sealed Ball Bearing” for automotive transmissions that reduces rotation torque by 80% compared to the conventional contact sealed type by adopting a proprietary shape of ultra-low friction seal.

There is an even greater demand to lower the torque in addition to a long life for transmission bearings along with better fuel efficiency for automobiles. Furthermore, there was an issue that drag torque was caused by seal contacting with inner ring. This is because in the past it was standard to use contact sealed type in order to realize longer operating life by preventing hard foreign matter such as gear wear debris generated inside the transmission. In addition, it was difficult to adopt contact sealed type for recent EV and HEV, which require high-speed rotation, due to the limit of the seal circumferential speed of the seal.

The currently developed “Ultra-low Friction Sealed Ball Bearing” has achieved an 80% rotation torque reduction when compared to conventional products and provides a low torque effect equivalent to non-contact sealed type by adopting a newly developed contact seal which arranges arc-shaped (half-cylindrical shaped) micro convexes at regular intervals on the sliding contact section of the seal lip. During rotation an oil film is formed between the sliding surfaces of the seal and inner ring due to the wedge film effect of the micro convexes. This greatly reduces the drag torque of the seal despite it being a contact sealed type. Also, because the seal lip convexes are microscopic, they allow lubricant to pass through but prevent harmful hard foreign matter from entering the bearing, which also maintains the bearing life.

NTN will propose this developed product globally and develop the market for it to contribute towards improvements in fuel efficiency for automobiles. Furthermore, this developed product was shown at “Automotive Engineering Exposition 2017” held at Pacifico Yokohama from May 24 to 26.

Features

(1) Rotation torque 80% reduction (compared to conventional products (contact sealed type))
(2) Bearing life under lubrication with foreign matter 5 times or more (compared to conventional products (non-sealed type))
(3) Seal circumferential speed 50 m/s or more (compared to conventional products (contact sealed type) 2 times or more)

Application

  • Transmission bearing, differential bearing

Inquiries about this release

Inquiry Form

Product photo

“Ultra-low Friction Sealed Ball Bearing”“Ultra-low Friction Sealed Ball Bearing”
Cross-section view of the developed product
Cross-section view of the
developed product
Arc-shaped (half-cylindrical shaped)
micro convexes arranged on the
developed seal (cut view)
(5 convexes are shown in the above cut view)
Torque measurement resultsTorque measurement results

Print