Axial Preload Method for Bearing Hub Units
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Solution Overview
Problem
Existing bearing hub units for motor vehicle applications face challenges in achieving high performance and stiffness due to limitations in axial preload, leading to increased weight and cost, especially when integrating with constant velocity joints.
Innovation Solution
A method for axially preloading a bearing hub assembly by compressing a radially outer ring, generating pressure between rolling bodies and their tracks, which increases the axial preload without altering the radius of fixing axes, allowing for increased pitch diameter and reduced weight and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the pitch diameter of the bearing is increased to improve stiffness and performance, then the bearing stiffness is improved, but the weight and volume increase dramatically
Solution Approach 1:
The bearing is preloaded axially during assembly to eliminate axial clearance and establish optimal contact conditions between rolling bodies and raceways before the bearing enters service. This preliminary action of preloading allows the bearing to achieve high stiffness and performance at the design pitch diameter without requiring a larger pitch, thereby avoiding the weight penalty that would result from increasing the pitch diameter to compensate for lack of preload.
2Ease of manufacture
If the bearing is designed with axial clearance for standard applications, then the manufacturing and assembly are simplified, but the bearing cannot achieve high performance under heavy load conditions
Solution Approach 1:
The bearing incorporates a preload mechanism that applies axial preload during assembly, transforming the bearing from a standard design with axial clearance to a high-performance design with optimized contact conditions. This preliminary loading action eliminates axial play and ensures proper distribution of loads across rolling bodies, enabling the bearing to handle heavy loads reliably while maintaining standard pitch dimensions and manufacturing processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enhances the bearing's stiffness and performance by increasing the distance between pressure centers, reducing weight and cost, and enabling the use of a single inner ring design with axial preload, improving the bearing's durability and reducing material usage in the suspension upright.
Implementation Method 1
a compression device (300) adapted to compress the radially outer ring (31) in an axial direction
Implementation Method 2
generating pressure between rolling bodies and their tracks
Data Source
AI summary
A method for axially preloading a bearing hub assembly having a rotatable hub, provided with rolling tracks and a bearing unit having a stationary radially outer ring, provided with rolling tracks, and a double row of rolling bodies disposed between the radially outer ring and the hub. The method requires the use of a bias unit and provides the following steps: a) feeding to an assembly station a hub bearing assembly, already assembled; b) verifying the value of the interference (C) between the radially outer ring and the bias unit; c) exerting an axial force (F) radially on the outer ring for the bias unit to deform under compression the radially outer ring that in turn will transmit a force to the rolling bodies via the raceways.