Electric Heavy-Duty Truck Design: Which E-Powertrain is Better – Direct Motor or Electric Axle? #ev

Summary

This video dives into the electrification of heavy-duty vehicles, focusing on electric powertrain systems like central direct drive, electric drive axles, and distributed drive systems. It covers key trends, such as the integration of components for efficiency and the rise of dual motor drives for better power distribution. The video also compares different powertrain configurations, highlighting their advantages and drawbacks in terms of cost, space, handling, and efficiency. With examples from real-world systems, it provides insights into the future of electric trucks, including emerging technologies like distributed electric axles.

Takeaways

• ⚡ Electrification of heavy-duty vehicles (e.g., semi-trucks) involves different electric powertrain systems, categorized into central direct drive, electric drive axles, and distributed drive systems.
• 🔩 Electric drive systems are becoming more integrated, combining motors, gearboxes, and controllers into compact units to improve efficiency, reduce weight, and save space.
• 🚛 Central direct drive systems are cost-effective for converting fuel-powered trucks into electric trucks, but they limit battery space and can negatively affect vehicle handling and comfort.
• 🛠️ Dual motor drive systems are increasingly adopted, offering better power distribution, improved energy efficiency, and enhanced performance for heavy loads.
• 🛞 Electric axles, especially parallel axis types, eliminate the need for drive shafts, improving system efficiency and providing more space for battery placement.
• ⚙️ Coaxial electric axles create a more compact power system and are typically used in light trucks, while vertical axis electric axles reduce installation costs but offer lower transmission efficiency.
• 🔌 Distributed drive systems, like wheel hub and wheel-end drives, offer fast response times but present challenges in motor control and increase unsprung weight, affecting vehicle handling.
• 💡 Wheel hub motors simplify vehicle structure and improve space utilization, but they increase unsprung mass, affecting handling, and require additional mechanical braking systems.
• 📉 E-axles reduce vehicle weight and improve battery placement compared to central direct drive systems, making them more efficient for large trucks and future hydrogen fuel cell applications.
• 🔧 Brogan offers a range of electric drive systems with dual motor configurations, optimizing power output, efficiency, and handling for heavy-duty vehicles, including unique technologies like uninterrupted power systems and distributed drive electric axles.

Q & A

What are the three main configurations of electric powertrain systems discussed in the script?

The three main configurations are central direct drive, electric drive axles, and distributed drive systems.

What is one of the key trends shaping the development of e-powertrain systems for commercial vehicles?

One key trend is the growing integration of electric drive systems, where motors, gearboxes, controllers, and other components are combined into a compact unit to reduce weight and space while improving efficiency and reliability.

What are the benefits of using a dual motor drive system in heavy-duty vehicles?

Dual motor drive systems offer better power distribution, improved energy efficiency, stronger electric drive capabilities, better heavy load performance, and greater operational efficiency, especially for tasks like hill climbs.

Why is the central direct drive system considered the most cost-effective approach for converting fuel-powered trucks to electric vehicles?

The central direct drive system allows for minimal changes to the original truck chassis, making it a faster and more affordable solution for manufacturers compared to developing a new platform for electric trucks, which would require significant financial and human resources.

What are some of the disadvantages of converting fuel-powered trucks to electric using the central direct drive system?

Disadvantages include limited space for battery packs, restricted driving range, poor handling and comfort due to improper weight distribution, and the need for suspension system reinforcements.

What is the difference between the parallel axis type and the coaxial type of electric drive axles?

The parallel axis type positions the motor parallel to the axle, commonly used in heavy-duty vehicles, while the coaxial type aligns the motor with the axle housing, creating a more compact structure, typically used in light vans and trucks.

What are the advantages and disadvantages of using wheel hub drive technology?

Advantages include simplified vehicle structure, better space utilization, higher transmission efficiency, and flexibility in driving configurations. Disadvantages include increased unsprung mass, handling issues, limited electric braking capacity, and challenges related to sealing and cooling.

Why is the distributed drive system advantageous for intelligent driving systems?

The distributed drive system offers fast response times and precise torque control, which are beneficial for intelligent driving systems, as it allows for better handling of various driving conditions.

What are some of the key benefits of the distributed drive electric axle for heavy-duty vehicles?

Key benefits include 100% torque recovery, a 10-15% reduction in energy consumption compared to direct drive systems, improved cargo capacity, regenerative braking capabilities, and precise torque vector control.

How does the growing adoption of hydrogen fuel cell systems impact the design of electric axles?

Hydrogen fuel cell systems require more chassis space than pure electric trucks, making electric axle designs with high integration and greater efficiency—such as the distributed electric axle—more suitable for maximizing chassis space and performance.