Amid the trend toward lightweighting in new energy vehicles, how can rubber chassis bushings achieve weight reduction without compromising performance?
Publish Time: 2025-10-08
Driven by the "dual carbon" goals, new energy vehicles are accelerating their development toward lightweighting, high energy efficiency, and long driving range. As a key component in vehicle weight reduction, the chassis system not only requires the use of lightweight materials such as aluminum alloys and high-strength steel, but also faces the daunting challenge of achieving weight reduction without sacrificing performance: rubber chassis bushings, its critical connection and cushioning components. Simply reducing the size or material of traditional bushings often leads to unbalanced stiffness, reduced vibration isolation, or shortened fatigue life, which in turn affects handling stability and ride comfort. However, through material innovation, structural optimization, and process upgrades, rubber chassis bushings have successfully struck a precise balance between lightweighting and high performance.1. High-performance rubber materials achieve "less weight, more power"The primary path to lightweighting is material upgrading. Traditional natural rubber or styrene-butadiene rubber, while low-cost, suffer from limited strength and durability. Chassis bushings for new energy vehicles commonly utilize high-performance materials such as hydrogenated nitrile rubber (HNBR), EPDM (ethylene propylene diene monomer) rubber, or thermoplastic elastomers (TPEs). These materials offer higher tensile strength, tear strength, and dynamic fatigue life per unit volume, allowing them to reduce rubber usage while maintaining or even improving mechanical properties. For example, HNBR offers excellent oil and heat resistance, making it suitable for high-temperature, oily environments near motor mounts. EPDM, on the other hand, excels in ozone and weather resistance, making it suitable for bushings exposed to the chassis' exterior for extended periods. This improvement in material quality provides the foundation for reducing material quantity.2. Topology Optimization for Precise Weight ReductionUsing computer-aided engineering and topology optimization techniques, engineers can remove redundant material from non-load-bearing areas of bushings while ensuring the integrity of critical load paths. For example, hollowing, thinning, or partially hollowing the bushing's rubber body reduces weight without compromising overall stiffness distribution. Furthermore, by adjusting the rubber thickness and metal frame shape, nonlinear stiffness control is achieved—softening at small amplitudes for improved comfort and stiffening under high loads for enhanced support. This "intelligent stiffness" design enables bushings to precisely meet the dual requirements of handling and vibration filtering for new energy vehicles while maintaining a lighter structure.3. Balancing Lightweight Metal Frames with High Bond StrengthChassis bushings are typically rubber-metal composite structures, with the metal frame comprising a significant portion of the total weight. To reduce weight, manufacturers use high-strength thin-walled steel tubes or aluminum alloy frames instead of traditional thick-walled steel components. Surface treatments such as micro-sandblasting, phosphating, or plasma treatments are used to enhance the rubber-to-metal bond. The integrated vulcanization molding process ensures a strong bond between the rubber and the frame under high temperature and high pressure, preventing debonding failure under long-term alternating loads. Even with a thinner frame, its structural integrity and interface reliability are maintained, achieving "light frame, strong bond, and stable performance."4. System-level Matching Optimization Unleashes Weight Reduction PotentialBecause new energy vehicles eliminate engines and adopt an integrated chassis platform, their vibration characteristics differ significantly from those of traditional fuel-powered vehicles. High-frequency vibrations from the motor are more pronounced, and the battery pack increases vehicle mass but lowers the center of gravity. Bushing design is no longer conducted in isolation; it is instead collaboratively simulated and optimized with the suspension, subframe, and electric drive system. By precisely matching the vehicle's modal data with the excitation frequency, the bushing provides "flexible vibration isolation" in specific directions while providing "rigid support" in others, achieving optimal vibration isolation efficiency with minimal material. This system-level approach ensures lightweight bushings not only maintain performance but also improve the overall vehicle's NVH performance.In summary, lightweighting new energy vehicle chassis bushings is not simply a matter of "subtraction," but rather a "precise weight reduction" achieved through high-performance materials, intelligent structures, advanced processes, and system integration. While reducing unsprung mass and improving range, it also maintains vehicle handling precision, ride smoothness, and long-term reliability. This truly achieves "lightness" without sacrificing quality, and "reduction without weakening," epitomizing the advancement of new energy vehicle chassis technology.
