The Green Transformation of Automotive Engine Mounts

The roar of a car engine stands as a symbol of industrial civilization, yet the accompanying vibrations and noise remain persistent challenges. Engine rubber mounts—these seemingly insignificant components—quietly perform the crucial role of isolating vibrations and reducing noise. However, traditional rubber mounts often rely on non-renewable petroleum-based synthetic rubber, conflicting with increasingly stringent environmental regulations and sustainability principles. The automotive industry now faces the critical challenge of developing high-performance, environmentally friendly materials for engine mounts.

Automotive engine mounts, also known as engine bushings, serve as critical components connecting the engine to the vehicle frame. Their primary function involves absorbing and dampening engine vibrations, reducing noise, enhancing ride comfort, and protecting engine components from vibration damage. Conventional mounts typically use injection molding processes with rubber or elastomer composites as core materials.

Natural rubber has been widely used in mount manufacturing due to its excellent elasticity, wear resistance, and damping properties. However, as environmental awareness grows and sustainability becomes paramount, traditional rubber mounts reveal significant drawbacks. Natural rubber supply faces geographical and climatic limitations with volatile pricing, while certain synthetic rubbers (like polyurethane) involve harmful production processes and present recycling challenges.

To achieve sustainable transformation, researchers have developed a novel composite material combining natural rubber (NR), thermoplastic polyurethane (TPU), and sisal fiber. This combination offers distinct advantages:

• Natural Rubber (NR): A renewable resource with exceptional elasticity and vibration absorption properties, featuring relatively eco-friendly production processes.
• Thermoplastic Polyurethane (TPU): Offers superior mechanical properties and recyclability compared to conventional synthetic rubbers, while enhancing NR's oil resistance, heat resistance, and aging performance.
• Sisal Fiber: A natural plant fiber providing high strength, low density, and biodegradability. As reinforcement filler, it improves stiffness while reducing dependence on petroleum-based materials.

The research employed an integrated design approach combining TRIZ (Theory of Inventive Problem Solving), morphological analysis, and the Analytic Network Process (ANP) to develop optimal mount designs.

The methodology incorporated three key TRIZ principles:

• Parameter Changes: Optimizing geometric and material parameters for vibration control
• Phase Transitions: Exploring smart materials for adaptive vibration damping
• Composite Materials: Combining material advantages for superior performance

This systematic approach generated numerous conceptual designs by analyzing structural configurations, material combinations, and connection methods.

The Analytic Network Process evaluated four finalist designs against multiple criteria including vibration damping, mechanical performance, environmental impact, cost, and manufacturability.

The research produced four distinct design concepts:

• Design 1: Conventional cylindrical structure with optimized internal damping features
• Design 2: Innovative conical structure enabling frequency-adaptive vibration control
• Design 3: Multilayer composite structure with graded material properties (selected as optimal solution)
• Design 4: Smart material design using magnetorheological fluid for adjustable damping

The selected Design 3 demonstrated exceptional vibration damping, mechanical properties, environmental benefits, and favorable manufacturing economics.

This research establishes a foundation for sustainable engine mount development. Future work should focus on:

• Further material optimization for enhanced performance
• Structural refinement using computational analysis
• Comprehensive vehicle testing for performance validation

As the automotive industry progresses toward sustainability, such innovations in vibration control technology will play an increasingly vital role in creating environmentally responsible transportation solutions.