Oshkosh's electric drive technology

The ProPulse system from Oshkosh Truck Corp. uses a diesel engine to power a large electric generator, which provides direct power to the wheels.

Oshkosh Truck Corp. has unveiled new diesel-electronic propulsion technology known as ProPulse that is designed specifically for the performance demands of heavy-truck applications. The company is a founding partner in the 21st Century Truck Initiative, a cooperative research partnership between government and industry that focuses on improving fuel economy, reducing air pollution, and reducing dependence on petroleum-based fuels through the development of new propulsion technologies, fuel cells, and vehicle design.

"Even before we became a founding member of the 21st Century Truck Initiative earlier this year, we were working on providing our customers with an economically viable alternative propulsion system," said Robert G. Bohn, Chairman, CEO, and President of Oshkosh Truck. "We wanted our customers, including the U.S. military, to have a propulsion system that improved vehicle performance, reduced dependency on petroleum-based fuels, and kept our air cleaner. ProPulse is the type of technology that will revolutionize the way heavy trucks perform. And this will have a major influence on the transportation industry."

Oshkosh plans to integrate this new truck propulsion technology into specialty trucks for defense and commercial customers. Oshkosh is responsible for all phases of ProPulse technology development, from design and testing to integration and production. The company intends to make the technology available in its line of aircraft rescue and fire fighting vehicles within two years. Oshkosh has been working on hybrid electric-drive technology for several years in cooperation with Rockwell Automation and other industrial partners.

The ProPulse system design uses a unique, modular series-hybrid arrangement to simplify the transmission of power to the wheels. The diesel engine powers a large electric generator, which provides direct power to the wheels, eliminating the torque converter, automatic transmission, transfer case, and drive shafts. Each differential is driven independently by a dedicated motor, controlled from its own power converter.

A dedicated electric motor, controlled from its own power converter, drives each differential independently.

"This is breakthrough technology in the world of heavy trucks," said Bohn. "It's one thing to develop alternative drive technology. It's another thing entirely to develop affordable electric-drive technology that can be integrated into some of the most high-performance trucks in the world."

Oshkosh claims the ProPulse technology can increase fuel economy by up to 40% over conventional powertrains. The diesel engine is optimized for operation between 1500 and 1800 rpm. Operating the engine at those levels eliminates the inefficiency associated with changing rpm levels during acceleration and deceleration and reduces emissions. Another advantage of the ProPulse control system generates historic and real-time diagnostic data for preventive system adjustments, allowing operators to schedule maintenance in advance to maintain peak performance.

The system offers direct wheel-torque control, in which each wheel can be individually controlled within 0.01% increments. This feature maximizes power regardless of field conditions. When traction drives are disconnected, the alternator is free to generate up to 500 kW (670 hp) of electricity, enough to supply peak power for 25 homes.

Goodyear tires wired for data

Goodyear's intelligent tire system consists of a lightweight sensor about the size of a hockey puck that is fastened to the inner-liner and measures cavity temperature and pressure.

Goodyear has introduced an intelligent tire system to help control tire costs and lower downtime due to tire issues in mining operations. The company originally introduced the development during MINExpo 2000, which featured a live data feed of the system in use at the Fording River mine in Elkford, BC, Canada.

Goodyear equipped a 218-t (240-ton) truck with the intelligent tire system on 40.00R57 tires. Each of the truck's six tires was fitted with an intelligent transponder to record tire temperature and pressure. The data was logged through a mine-management system from Modular Mining Systems at the mine and downloaded via software at Goodyear's MINExpo exhibit, where it was displayed graphically.

"The 7.6-cm (3-in) diameter, 3.3-cm (1.3-in) thick, lightweight intelligent tire sensor, about the size of a hockey puck, is fastened to the tire inner-liner, where it measures cavity temperature and pressure and transmits data every three minutes," said Goodyear OTR Engineer Darrin Landes.

This 218-t (240-ton) haul truck was one of three test beds for Goodyear's tire system.

An in-cab receiver, which can be programmed with each tire's identification and the truck number, logs data. It sends the data "upstream" to the mine-management system unit in the cab.

Based on the mine's preference, the data can then be viewed at mine dispatch, downloaded into a laptop computer, or viewed in the truck. The system is compatible with Modular Mining's mine-management system.

"Operators can now see, on a real-time basis, which tires are getting hot and adjust routes accordingly," Landes said. "This is the most significant benefit of the system since excessive heat is a tire's worst enemy."

An optional, in-cab receiver/display unit that displays temperature and pressure can be programmed with each tire position and functions like a stand-alone receiver. Goodyear field engineers and mine managers placed more than 250 transponders in service last year.