The New York City Department of Sanitation has begun field testing Bosch Rexroth's Hydrostatic Regenerative Braking parallel hydraulic hybrid system.
The city wants to gauge the system's use for the department's refuse trucks. If the system checks out technically and economically, the department may install the technology in all existing and new fleet vehicles.

The hydraulic hybrid testing is part of a larger initiative by the department to assess the benefits of alternative drive technologies, especially with the potential for reducing fuel consumption and emissions.

Testing will take place in all five boroughs, to see how fuel efficiency and other aspects hold up in different neighborhoods, seasonal conditions and operating environments. The assessment will include braking tests, acceleration tests, route collection tests and dynamometer testing.

"The HRB system provides optimum fuel efficiency when vehicles undergo frequent braking and acceleration," said Michelle DuHadway, manager of parallel HRB accounts at Bosch Rexroth. "We're excited to see the system tested in a wide variety of settings, to obtain more real-world data that shows the HRB system can provide significant fuel savings and emissions reduction."

Used in a Crane Carrier Company LET2 truck and integrated with a Heil Environmental refuse body, the HRB system is equipped with a hydraulic pump, which is connected to the driveline. This pump sucks up energy from the driveline and imparts a retarding force on the drivewheels, pumping hydraulic fluid into a nitrogen-pressurized accumulator. While accelerating, pressurized gas pumps fluid out of the accumulator. The pump then performs as a hydraulic motor, helping the engine and decreasing the fuel required to launch the vehicle, a process known as regenerative braking.

"Bosch Rexroth's hybrid HRB technology and system can be integrated into most medium- and heavy-duty truck vocations without impacting the vehicle's configuration," said Crane Carrier Company's Glenn Pochocki, vice president of sales and marketing for refuse/chassis products. "The HRB system is designed to improve the vehicle's fuel economy, while improving brake system life with improved acceleration."

This is not the first time the company's technology has been tested in an urban environment. "We started our in-field testing of HRB last summer with a refuse customer in Berlin, Germany and are now introducing this proven technology in North America," said Ed Greif, vice president of engineering development hydraulics. "Field testing has verified our simulations and we anticipate similar success in the U.S."

Hydraulic hybrid systems are made to capture a large portion of the braking energy, which can lead to reduced brake maintenance costs and vehicle downtime benefits. The system is able to slow the vehicle without utilizing the foundation brakes as much, and this process expands the life cycle of the truck's brakes.

On average, the Department of Sanitation replaces brakes approximately once a year, which takes the truck out of service for at least two days. The department hopes to improve that figure by 50 percent or more with this technology.

Bosch Rexroth is a division of the Bosch Group, a leading global supplier in the areas of automotive, industrial, consumer goods and building technology, according to the company. The company has been involved in hybrid technology for more than 30 years.

More info: www.boschrexroth-us.com.