Oshkosh Hybrid Truck The HEMTT A3

The Oshkosh Hybrid Truck

The HEMTT A3 (Heavy Expanded Mobility Tactical Truck) is according an Oshkosh press release the first production-ready, tactical military truck powered by an energy efficient diesel-electric drive system, called ProPulse®, that can increase fuel efficiency by 20 percent or more, depending on mission profile.

The HEMTT A3 is a heavy-payload, up to 13 tons, truck and is equipped with heavy-duty TAK-4® independent suspension that keeps the wheels on the ground, even in extremely rugged terrain, and combined with direct-drive, electrically driven wheels, can provide torque where it is most needed. The HEMTT A3 has height-adjustable suspension, which facilitates self-unloading of supplies.

 Here you can clearly see the semi-active hydragas strut independent suspension system.

The truck has the ability to do double duty as a 200-kilowatt generator, has onboard diagnostics for simplified in-the-field troubleshooting and maintenance. Features a power pack - its engine/generator and charging system - that can be removed and replaced in30 minutes or less, greatly reducing down time and simplifying in-field maintenance of major components.

ProPulse®

Oshkosh next-generation hybrid propulsion system ProPulse® provides several benefits for fleet performance:

• Improves fuel economy by up to 40 percent over conventional power trains in harsh terrain.
   
• Smaller logistics footprint. Since the system uses no batteries, they never need to be replaced. Rather, ultracapacitors are used for energy storage, and the amount of fuel needed to supply ProPulse-equipped trucks is less.
   
• On-board generator. The system acts as an on-board generator, providing enough electricity to power a city block, airfield, hospital or command center.
   
• Reduced heat signature. The truck can sit silently, draw on the ProPulse system to power equipment, and yet generate no heat signature since the engine doesn't need to be running.
   
• Advanced safety technology. Unlike some other systems, users can discharge all stored energy from the truck, so maintenance personnel can work in complete safety.
   

The ProPulse system uses a unique, modular series-hybrid arrangement to simplify the transmission of power to the wheels. The diesel engine powers an electric generator, which provides direct power to the wheels, eliminating the torque converter, automatic transmission, transfer case and drive shafts. The system has no batteries, using ultracapacitors for energy storage instead. A regenerative braking function stores engine energy and then uses it to assist in the next braking operation, reducing wear and tear on the brake system.

This leading-edge technology is the first significant step toward the development of an entirely new generation of highly mobile and incredibly efficient defense trucks. Oshkosh focus is on enhancing performance characteristics while reducing the logistics footprint and making trucks more environmentally friendly

Specifications

• Engine: 400 HP Cummins ISL Diesel
• Generator: Marathon 305KW
  (200KW exportable power)
• Energy Storage: 1.5 MJ Ultra-capacitors
• Drive Motors: Moog – 460 VAC
• Frame: Rectangular Tube
• Suspension: Oshkosh TAK-4/Variable Height
• Axle Gearing: 2-speed Gearing with Planetary Wheel Ends
• Brakes: Air Disc with ABS
• Wheels: Aluminum
• Tire: 395/85R20 XZL Michelin with CTIS
• In additions the HEMTT A3 has enhanced the HEMTT Performance with regard to:
  • 16 inches shorter length
  • 3,000 lbs. lighter
  • More stable/maneuverable
  • 11 inches lower payload CG
  • 40% roomier cab
  • 20% better fuel economy
  • Improved crew comfort
  • Improved crew safety
  • Modular design
  • Reduced logistics footprint

This article is based on promotional material from Oshkosh with more focus on the hybrid drive train than military matters.