Kohler says its KDW 1003 diesel engine with a continuously variable transmission (CVT) makes up a drivetrain that "combines the simplicity of driving a traditional automatic transmission (with continuously variable ratio) with the precision of a typical automotive gear box." Rated at 26.1 hp (19.5 kW) at 3600 rpm, the three-cylinder, liquid-cooled diesel package is applicable for a variety of off-highway vehicles such as UTVs, quads, and snow machines, as well as wheeled or tracked off-road equipment. The KDW 1003 also meets current U.S. EPA and CARB emissions requirements.
According to Cam Litt, Marketing Manager, Kohler Engines, “All the development work—tuning the CVT to the engine’s horsepower and torque—has already been done for an OEM. Kohler’s mechanical CVT product was developed and field tested by our Lombardini diesel engine brand in Italy, whose similar product has already been specified by OEMs in Europe and India to power off-road vehicles.”
An advantage of a CVT is its ability to maintain engine speed in its optimum power output range for all operating conditions. Unlike a conventional transmission that changes the ratio in stages by shifting gears, the ratio is continuously varied in a CVT, as its name implies.
Currently used to a great extent in the automotive market, CVT benefits most often cited include more usable power, better fuel economy, and smoother driving experience than a traditional automatic transmission.
The KDW 1003’s overall compact size allows it to be positioned between the vehicle’s four wheels, contributing to increased stability. It also features an engine braking system available in a slowing-down phase right up to the vehicle completely stopping.
Kohler says the CVT requires almost no maintenance because of a simplistic design featuring a minimal number of parts, while the powertrain has a sealed and air-cooled compartment to extend the belt life and prevent slippage.
The KDW 1003’s gear box incorporates two forward gears (low/high) and a reverse reduction gear specifically designed for off-highway work vehicles. It also features a speed sensor, gear selection sensor, and users have the option of two- or four-wheel drive functionality.
Kohler's newest Tier 4 Final-compliant diesel engine is the single-cylinder KD 420. Expanding to five Kohler's overall lineup of T4F engines, it features exhaust gas recirculation (EGR) and tuning enhancements to fuel timing, fuel injector, and injector pump systems.
With a gross power output of 9.8 hp (7.3 kW) at 3600 rpm, and a peak torque of 17 lb·ft (23 N·m) at 2200 rpm and a fuel tank capacity of 5 L (1.3 gal), applications for the KD 420 include a wide range of commercial, industrial, and outdoor power jobs, including hydroseeders, water pumps, pressure washers, air compressors, two-wheel tractors, agricultural mowers, and portable power generators.