Development of third generation tapered roller hub unit for pickup trucks/full-size SUVs

JTEKT Corporation has developed the third-generation tapered roller hub unit for pickup trucks and full-size SUVs which have drastically improved performance compared with conventional hub units and enhanced reliability under harsh environments, such as desert and extremely cold regions. JTEKT group continues to see increasing sales for this product mainly in ASEAN and North America.

Since pickup trucks and full-size SUVs are heavy and are required to have longer lives in comparison to passenger vehicles, tapered roller bearings with their larger rating capacities are used in these hub units. In the past, the most common construction of the hub unit was one where the hub shaft and the inner ring raceways are separated (first-generation and second-generation models). However, in response to customers’ requirements for the improvement of automotive performance and reliability, JTEKT developed and began mass-producing the third-generation tapered roller hub unit. This hub unit integrates the inner ring on the outer side of the hub unit with the hub shaft and employs “LFT (Low Friction Torque)¹⁾”, JTEKT’s original low friction torque technology.

1.Features

(1) Achieves higher strength/rigidity and reduced weight
Through the integration of inner ring and shaft (development of third generation), the shaft strength has been improved by 20 times together with approximately 600 g in weight reduction per vehicle, compared with the conventional product.

(2) Improved performance under harsh environments
Achieves over twice the resistance to muddy salt water of the conventional product through optimized seal design (lip design, rubber material and grease on lip)

(3) Reduced frictional torque
50% reduction in drag torque compared with the conventional products through optimized seal design and JTEKT’s original low friction torque technology “LFT (Low Friction Torque)¹⁾”

(4) Improved quietness
Reduced brake vibration by improving runout accuracy of the shaft flange.

 1)Refer to the data shown below for the details of LFT (Low Friction Torque).
JTEKT Engineering Journal No. 1007E (2010) Page 47 to Page 53
Super-low Friction Torque Technology of Tapered Roller Bearings for Reduction of Environmental Burdens

*LFT is a registered trademark of JTEKT Corporation.

2.Product photo

*Left: For driving wheel Right: For driven wheel

(Cross-section figure)

*Left: For driving wheel Right: For driven wheel

3.Sales plan

4.Manufacturing plant

Richland plant of KOYO BEARINGS NORTH AMERICA LLC (South Carolina)