Water Pump Drive
Because engine driven water pumps are tied to engine speed they are open loop sub-optimal systems; they produce more flow and pressure at cruise speeds than is needed. At the same time, demands on the pump are highest when the vehicle is not moving and the engine is idling. Sizing a pump for this condition leads to wasted energy when the engine is above idle speeds.
A water pump drive incorporating NuVinci® CVP technology provides better performance and more economy by separating the engine speed from pump speed. This enables the pump to work in its operational range based on demand regardless of engine speed. As a result, a NuVinci Optimized accessory drive delivers the ideal speed all the time – optimizing pump operation and performance, and thereby enhancing engine performance which increases system efficiency and improves fuel economy. Best of all, it does all this with minimal complexity, easy installation and low cost.
- Reduced fuel consumption during highway cruising compared to conventional fixed-ratio water pump drives
- Pump speed is now independent from engine speed
- Closed loop engine temperature control by changing water pump speed
- Quiet, smooth, transparent operation
- Flexible packaging enables use of existing belt lines or engine PTO
The NuVinci technology enables a practical accessory drive that measurably improves fuel economy by separating accessory speed from engine speed.
During a typical drive cycle, engine speeds operate between idle and highway cruise depending upon conditions. For vehicles with belt-driven accessories, accessory speeds follow these transients, wasting power when the engine is accelerating or cruising. With the NuVinci-equipped accessory drive mounted on the crankshaft, belt speeds may be varied independent of engine speed, reducing accessory speeds and power consumption.
By maintaining steady accessory speed, both performance and economy improve. At higher engine RPM, decreasing accessory speeds decreases power use, thus saving energy. Additional energy savings can be gained by optimizing the accessories for a narrow speed range operation. Conversely, at low engine RPM, the accessory belt speed can be increased to provide additional battery-charging power or to increase the water pump speed.