PRZOOM - /newswire/ -
Castleton, NY, United States, 2007/05/04 - Folsom Technologies has developed a line of hydromechanical continuously variable transmissions (CVT) that are configurable either as a standalone CVT or as the CVT component of a hydraulic hybrid system.
Folsom Technologies hydromechanical CVTs offer infinite ratio coverage from full reverse through neutral to full forward and, because they incorporate a high efficiency hydraulic pump and motor, they can form the core element of a hydraulic hybrid drivetrain.
At the 2007 New York International Auto Show, the company displayed its 50/100hp CityCar CVT. This unit is designed to go into passenger vehicles of up to 100hp but, because of its compact size and weight, it is also suitable for application in small city cars of 50 hp.
The company is also developing the second-generation of a 350hp full-size rear wheel drive (RWD) passenger vehicle unit that has been specifically designed to be integrated into a hydraulic hybrid system. Both this and the CityCar transmissions are currently undergoing in-vehicle development and are being used for technology demonstration.
Instead of using commercial hydraulic units, Folsom designed its own hydrostatic pump/motor, focusing not just on efficiency but also on size—the transmissions are designed to be a drop-in alternatives for existing transmissions—as well as cost.
For a hydraulic hybrid application, the CVT needs to be paired with a set of accumulators and flow valves. For passenger car applications, Folsom sees its transmissions enabling mild, parallel hybrid functions: regenerative braking, launch assists, acceleration assist and engine starting (for a start-stop function), in addition to normal CVT operation.
“Increasing vehicle fuel efficiency and emissions reduction is a high priority and many technologies are becoming available to facilitate these goals,” said Lawrence Folsom, president of Folsom Technologies. “Hybrid vehicles have proven success in increasing vehicle efficiency and hydraulic hybrids offer significant benefits over electric hybrids as they can recuperate a greater percentage of the energy normally lost during braking. Hydraulic braking energy recovery, which is an available feature of our CVT, offers significant gains in fuel economy and reductions in emissions, as well as greatly reduced brake wear. For operating duty cycles that have frequent start/stops (such as taxis, school buses, garbage haulers, etc.) the fuel savings can be greater than 50%. Combining the known benefits of a continuously variable transmission with hydraulic energy recovery has the potential to maximize vehicle efficiency gains. Our hydromechanical CVT combines two major vehicle improvement technologies into one compact package”.
The control logic for the different applications is currently being developed by a Tier 1 supplier, according to the company. A number of different CVT applications are currently being developed by Folsom Technologies, including one for a Class III truck, and they expect the first transmission will reach production status in about 3 years. All CVTs are custom designed and are configured to be drop-in replacements for the vehicle's original transmission.
In addition to highway and off-highway vehicle applications, Folsom Technologies has configured their hydromechanical CVTs for the lawn and garden equipment and other industries. “The ability to change ratio seamlessly from full reverse through neutral to full forward without the need for a clutch results in a compact and cost efficient system,” said Lawrence Folsom.” It offers the excellent creep characteristics of hydrostatics yet has very high efficiency throughout its ratio range.”
About Folsom Technologies
Folsom Technologies (fti-cvt.com) is a leading designer/developer of hydromechanical CVTs. The company also provides complete engineering services to the automotive and other industries from product concept to design release and validation. Technical expertise lies in driveline, vehicle engineering, process equipment and niche volume manufacturing.