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Special Edition

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Next-generation super-low friction torque tapered roller bearing LFT-IV

Contributing to Greater Fuel Efficiency with No.1 Low Friction Torque Performance

As a countermeasure to environmental issues such as global warming, there is an even greater demand to improve fuel efficiency of vehicles. In order to help solve this problem, JTEKT has developed a new-generation tapered roller bearing for use in cars with No.1 low friction torque performance.

Pursuing torque loss reduction from various angles

Many tapered roller bearings are used in the driveline units of vehicles, such as transmissions and differentials, and play a role in supporting each rotating shaft during the process of transmitting engine power to a vehicle’s tires. For this reason, a major point regarding the extent to which such bearings can contribute to better fuel efficiency is how much torque loss created by friction can be reduced. For a long period of time, JTEKT has engaged in research and development activities aimed at reducing the friction torque loss of tapered roller bearings from a variety of angles and, as a result, commercialized the LFT (Low Friction Torque) series. LFT-III, a product developed in 2006, successfully reduced torque loss by approximately 50 percent compared to JTEKT’s standard products of the same size. LFT-III is adopted by automotive manufacturers both in Japan and overseas and is significantly contributing to better fuel efficiency. Moreover, in 2017, JTEKT successfully developed LFT-IV, which has reduced torque loss by a further 30 percent or so compared to LFT-III.

The flow of lubricating oil is analyzed in order to find the optimal cage shape. Agitation resistance caused by lubricating oil has been greatly reduced.

External appearance of LFT-IV.
The cage is made of resin, which has high design flexibility

Reducing agitation resistance of lubricating oil to the greatest extent possible

Tapered roller bearings are used in units filled with lubricating oil. LFT-IV was developed with a primary focus on reducing agitation resistance, which occurs due to more lubricating oil flowing through the bearing than necessary, to the greatest extent possible. The approach taken was to make the part of a bearing referred to as the “cage” into a shape which minimizes the amount of lubricating oil that flows through the bearing using CAE (computer-aided engineering). In order to reflect the optimal cage shape found through CAE into the product, resin was used as the cage material instead of the conventional metal, due to its high design flexibility. By using this LFT-IV with its significantly lower torque, on differentials, a fuel efficiency improvement of 2.5 percent can be expected.
“Currently we are working on solving issues standing in the way of mass production for this product. I hope JTEKT continues to respond to the demand for low torque and contribute to society through technology.”

LFT-IV supports all vehicle models, from light vehicles to pick-up trucks.

*LFT(Low Friction Torque) is a registered trademark of JTEKT Corporation.