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Caterpillar receives EPA Clean Air Excellence Award
May 13, 2009 -- The U.S. Environmental Protection Agency today recognized Caterpillar Inc. for its outstanding innovative efforts to help make progress in achieving cleaner air. The company was one of 15 recipients from across the nation that received EPA 2008 Clean Air Excellence Awards at a ceremony in Washington, D.C.
Caterpillar was honored for developing its D7E, a revolutionary new bulldozer that consumes 10 to 30 percent less fuel and has 25 percent more dozing efficiency than previous models. The D7E also uses fewer parts and fluids during its useful life. Together, these changes significantly reduce carbon dioxide and gaseous emissions.
The most significant innovation behind this technology is a very compact alternating current electric drive train that replaces the power shift transmission typically used in this size tractor. With this design, Caterpillar has opened the door to new applications for electric drives in construction equipment and to higher productivity and fewer emissions.
“This is the kind of innovative technology we hope to see more of as we move toward a green economy,” said EPA Region 5 Acting Administrator Bharat Mathur. “We commend Caterpillar for taking steps to address climate change.”
This year’s award recipients were selected from 125 applicants and represent achievements in five categories: clean air technology, community action, education and outreach, regulatory policy innovations and outstanding individual achievement. These innovative air quality programs provide environmental benefits and create green products and jobs.
The awards program, established in 2000 at the recommendation of the Clean Air Act Advisory Committee, annually recognizes and honors outstanding innovative efforts to help make progress in achieving cleaner air. Award-winning entries must directly or indirectly reduce pollutant emissions, demonstrate innovation, offer sustainable outcomes and provide a model for others to follow.
Caterpillar D7E
On the Caterpillar D7E, the AC electric drive train replaces the power shift transmission that is typically used in this size track-type tractor. The technological challenges for electric drive trains in track-type tractors include frequent directional shifts, the need to have very powerful electrical components in a small amount of space (power density), the need to operate in mud and partially submerged in water, as well as making these components work under strong vibration levels.
The innovation of the D7E electric drive train is centered on AC electric technology controlled by solid-state semiconductors. This continuously variable speed, brushless motor design, combined with sealed and liquid-cooled components are the key breakthroughs that make this technology viable in a track-type tractor.
By overcoming the challenges involved with the designing of the D7E, Caterpillar has opened the door to new applications for electric drives in construction equipment. Now workers on jobsites across the Unites States can look forward to higher productivity and fewer emissions.