The working principle of customized automotive bearings is based on the principle of rolling friction. By customizing the structure and materials of the inner and outer rings, rolling elements, and retainers, combined with precision manufacturing processes, load bearing, speed adaptation, and environmental adaptability under specific working conditions can be achieved. The core mechanism can be divided into the following levels:
1. Basic principle: Rolling friction and load transmission
The core of customized automotive bearings still follows the principle of rolling friction, which converts sliding friction into rolling friction through the rolling of rolling elements (such as steel balls, cylindrical rollers, and tapered rollers) between the inner and outer raceway, significantly reducing the friction coefficient and achieving efficient energy transfer. During the customization process, the following parameters need to be adjusted according to specific working conditions:
Rolling element shape: spherical rolling element (with low load-bearing capacity and friction coefficient) suitable for high-speed bearings; Cylindrical or conical rolling elements (with high load-bearing capacity and friction coefficient) are suitable for low-speed heavy-duty bearings.
raceway shape: Circular arc-shaped raceway (with low load-bearing capacity and low friction coefficient) is used for high-speed bearings;
; Linear or conical raceways (with high load-bearing capacity and friction coefficient) are used for low-speed bearings.Retaining frame material: Steel, copper or plastic retaining frame affects the bearing life and wear resistance, and should be selected according to temperature and corrosive environment.
.2. Customized Design: Working Condition Adaptation and Performance Optimization
The core of customizing automotive bearings is to adjust the bearing structure and materials according to the vehicle type, usage scenario, and performance requirements, including:
Load Type Adaptation
Radial Load: When the wheel is traveling in a straight line, the bearing bears the reaction force between the tire and the ground. It is necessary to optimize the curvature radius of the raceway and the diameter of the rolling elements to ensure uniform load distribution.
.Axial load: If the bearing needs to withstand lateral force when the vehicle turns, it is necessary to increase the number of rolling elements or adopt a tapered roller design to improve the axial bearing capacity.
. Composite load: If the transmission gear bearings need to withstand both radial and axial forces, tapered roller bearings or double row angular contact ball bearings should be used to achieve load balance through angle adjustment.Speed and efficiency optimization
High speed working conditions: such as engine crankshaft bearings, lightweight materials (such as ceramic hybrid bearings) and precision grinding processes need to be used to reduce centrifugal force and frictional heat, ensuring stability when the speed exceeds 10000rpm.
. Low speed and heavy load conditions: For commercial vehicle axle bearings, high-strength steel (such as GCr15SiMn) and heat treatment processes are required to improve surface hardness (HRC60-65) and withstand loads of several tons.Environmental adaptability design
Corrosion resistance: For example, in coastal areas, vehicle bearings need to be made of stainless steel material or surface coating (such as zinc nickel alloy) to prevent salt spray corrosion.
.High temperature resistance: For new energy vehicle drive motor bearings, high-temperature resistant lubricating grease (such as polyurea based) and heat dissipation structure are required to withstand the working temperature of the motor above 200 ℃.
.Dustproof and waterproof properties: For off-road vehicle bearings, double lip sealing rings and labyrinth structures should be used to prevent mud and sand from entering.
.III. Manufacturing Process: Precision Machining and Quality Control
The manufacturing process for customized automotive bearings needs to meet the requirements of high precision and high reliability. The main processes include:
Material Selection and Pre treatment
Select high-quality bearing steel (such as GCr15) or special materials (such as ceramic and plastic composite materials), eliminate internal stress through spheroidization annealing, and improve cutting performance.
.Precision machining
Inner/outer ring machining: CNC lathes and grinders are used to control the dimensional accuracy within ± 0.001mm, with a surface roughness of Ra0.2 μ m.
. Rolling element processing: Through cold heading, grinding, and ultra precision grinding processes, ensure that the sphericity error is less than 0.5 μ m and the cylindricity error is less than 1 μ m. Processing of retaining frame: using stamping or injection molding technology to ensure hole accuracy and strength, and prevent deformation during operation.Assembly and Testing
Automatic Assembly Line: Through the use of robotic arms and visual inspection systems, precise assembly of rolling elements, cages, and inner and outer rings is achieved, avoiding human errors.
. Performance testing: including vibration and noise detection (below 5dB), high-temperature operation testing (150 ℃ for 48 hours), salt spray testing (72 hours without corrosion), etc., to ensure that the product meets ISO, GB and other standards.IV. Typical Application Scenarios
New energy vehicle drive motor bearings
Customization requirements: high speed (above 20000rpm), low noise (below 3dB), and high temperature resistance (200 ℃).
.Solution: Adopting ceramic hybrid ball bearings, combined with an oil air lubrication system, to reduce frictional heat;
; Optimize the structure through modal analysis to reduce vibration noise.Maintenance free bearings for commercial vehicle axles
Customization requirements: long life (over 500000 kilometers), heavy load resistance (10 ton level), dust and water resistance.
.Solution: Adopting double row tapered roller bearings, integrating sealing rings and grease chambers; Optimize the contact angle through finite element analysis to improve the uniformity of load distribution.
Racing steering system bearings
Customization requirements: high rigidity (increased torsional stiffness by 30%), lightweight (reduced weight by 20%), and fast response.
.Solution: Adopt thin-walled deep groove ball bearings, matched with carbon fiber retainers;
; Reduce unnecessary materials and improve dynamic performance through topology optimization.