Hub Unit Bearings
Hub unit bearings are integrated units that combine the bearing supporting an automotive wheel for rotation relative to the vehicle body with the hub and flange. They mainly use double-row angular contact ball bearings or double-row tapered roller bearings, and are classified by generation according to structure. The first generation is a bearing alone, the second generation has a flange on the outer ring, and the third generation integrates the hub wheel and the inner ring side as well. Compared with conventional assemblies, they help reduce the number of parts and assembly man-hours, and offer advantages in weight reduction and rigidity improvement. Types are available for driven wheels and non-driven wheels, and some models incorporate a rotation sensor or encoder for ABS. In recent years, products that reduce rotational torque through improved grease and seals, aiming to improve fuel economy and electric vehicle power consumption, have been increasing.
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Hub Unit Bearings
3rd Generation Ball Hub Unit (for Drive Wheels)
A 3rd generation ball hub unit supporting drive wheels. Low-friction bearings and seals reduce friction loss by 65% compared with conventional products, contributing to improved EV electric efficiency.
JTEKT Corporation
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Hub Unit Bearings
3rd Generation Ball Hub Unit (for Driven Wheels)
A 3rd generation ball hub unit supporting driven wheels. Combines low torque design with mud water resistance and suits a wide range of vehicles from kei cars to SUVs.
JTEKT Corporation
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Hub Unit Bearings
HUB-LFT Low-Torque Hub Unit
A low-torque hub unit for the four wheels of automobiles. Reduces torque with a dedicated grease and double axial lip seal.
JTEKT Corporation
How to choose Hub Unit Bearings
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1. Select a rating that matches the vehicle axle load
Hub unit bearings directly receive the vehicle weight and moment loads during cornering, so confirm that the axle load of the applicable vehicle falls within the product's rated range. The axle load range of the listed products is 4.9 to 19.7 kN. Insufficient margin against the axle load may lead to early flaking and play.
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2. Match P.C.D. and bolt count to the wheel
The pitch circle diameter of the wheel mounting holes and the number of hub bolts must match the wheel side, otherwise installation is not possible. The P.C.D. of the listed products is 100 to 139.7 mm, and the bolt count is 4 to 6. Verify against the vehicle's original equipment specifications when selecting.
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3. Match the generation (structural type) to the vehicle
The first to third generations differ in how they attach to the knuckle and how they are assembled with the hub. Select a generation that suits the vehicle design. The third generation excels in rigidity and weight reduction due to integration, but the bearing cannot be replaced alone and must be replaced as a complete unit.
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4. Confirm whether it is for a driven or non-driven wheel
Driven-wheel types have a spline hhole in the hub to accommodate the drive shaft. Their shape differs from non-driven types, and they are not interchangeable. Check the classification according to the vehicle's drive system and mounting position, such as FF, FR, or 4WD vehicles.
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5. Confirm compatibility with ABS sensors
Types with built-in rotation sensors or magnetic encoders supply wheel speed signals to ABS and vehicle stability control systems. If the sensor method on the vehicle side or the presence of a sensor or encoder does not match, the control system will not operate correctly.
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6. Compare low-torque performance and mud and water resistance
Improved dedicated grease and seal structures have achieved a 50% reduction in rotational torque compared with current products, contributing to better fuel economy and electric vehicle power consumption. On the other hand, reducing seal contact increases the risk of mud and water ingress. Therefore, also check whether mud and water resistance is ensured through structures such as labyrinth designs.
This guide was written by AI based on the listed products' documents and specification items. Check each manufacturer's documents before adopting.