Engineers at Dana Rexroth Transmission Systems have completed final validation testing of the R2 hydromechanical variable transmission (HVT), with the start of production expected in 2015 Q3. According to the company, field tests on working vehicles have shown fuel savings of up to 25% over traditional transmission designs, with additional savings possible through further optimization with equipment subsystems. A product of the joint venture between Dana Holding Corp. and Bosch Rexroth, the HVT R2 features a modular design that can be adapted for a variety of off-highway applications with net input power from 135 to 195 kW (180 to 260 hp), including front-end loaders, motor graders, industrial lift trucks, reach stackers, forestry skidders, and other off-highway applications. HVTs from Dana Rexroth reduce fuel consumption by decreasing engine speeds throughout the duty cycle and at idle, where speeds can be dropped to as low as 600 rpm. Application analysis demonstrates the possibility of further savings without compromising performance through engine downsizing.
Dana Rexroth HVTs enable sensitive, precise vehicle positioning with a stepless drive that offers improved acceleration while maintaining tractive effort. They optimize the operating point of the diesel engine by decoupling engine speed from drive speed, and maintenance costs are reduced by utilizing hydrostatic braking and wear-free directional reversing without clutches.
The HVT R2 is a modular platform that delivers a full suite of configuration options and software controls, such as direct or remote mounting, flexibility in shift control and drive strategy parameters, and the deployment of up to three power take-off pumps.
The HVT system designed by Dana Rexroth helps reduce complexity for equipment manufacturers, since the entire system of gears, clutches, and hydrostatic units is managed by an advanced electronic control unit and optimized for efficiency by a single supplier.
The HVT R2 will be exhibited by Dana as part of a 21-t (23-ton) drivetrain system for front-end loaders at Intermat in April.