Continuously Variable Transmission

SuperDrive is a continuously variable transmission (CVT) capable of heavy torque loads and high speeds with improved fuel economy and reduced emissions. A CVT is a totally automatic transmission that does not shift from one gear to another as the vehicle accelerates, but provides constant, smooth acceleration. The SuperDrive system is coupled to the crankshaft at the rear of the engine in the conventional location for transmissions. The unit installed in the transmission cavity incorporates an axial piston variable hydraulic pump and an axial piston variable hydraulic motor assembled as a single unit. In addition, the system includes a heat exchanger, a reservoir, and an electronic control module.

The system accomplishes management of the hydraulic pump and motor and the diesel engine through the electronic control module. The system performance differs from other CVTs and hydrostatic transmissions currently being offered primarily in the area of engine management. These other systems run the engine at a constant rpm. This provides good engine responsiveness and power, but is wasteful of fuel, particularly when the engine is lightly loaded. The SuperDrive engine management system provides the ability to obtain improvement in fuel economy.

SuperDrive uses a proprietary program that through the control module interfaces with the engine computer and the transmission. This program manages engine rpm and loading, and pump and motor swash plate position. Fuel economy is further enhanced by the ability of the system to reduce engine rpm while at road speeds. The SuperDrive system increases the ability to provide higher torque at lower engine speeds in effect acting like an overdrive, but providing the ability to continuously maximize the torque output to the rear wheels at all vehicle speeds. While the system can be marketed very effectively on fuel economy alone, it offers many other desirable features:

-Emissions can be reduced in some proportion to fuel savings.

-The system has far fewer moving parts than conventional transmissions.

-The engine operates at lower rpm and at lower temperature.

-The engine is soft-coupled to the load through the hydraulic transmission so shock loading to the rear main bearing is eliminated.

-Because it operates as an automatic transmission, drivability is excellent and driver fatigue is reduced.

-The system provides dynamic braking which extends the life of the mechanical brakes and eliminates the need for any separate engine braking devices.

-Reduced operating and maintenance costs.

-Reduced downtime for maintenance.