Behr America says it will introduce a new demand-driven coolant pump system, promising fuel-economy savings of up to one percent in heavy trucks.
Behr’s says its patented Visco technology for engine-coolant pumps reduces “parasitic” power losses that affect fuel economy. First introduced on 13-liter diesel engines in Europe, Behr’s new demand-driven system recently became available on commercial vehicles sold in North America.
The electronically-controlled Visco system varies coolant-pump speeds based on engine requirements and operating conditions. Heavy-truck coolant pumps today are almost exclusively tied linearly to engine-speed via belt drives, Behr says. Since these pumps are designed to meet coolant requirements under maximum load conditions, flow rates at many operating points exceed actual need with a resulting drain on fuel economy.
Behr’s Visco technology covers variable-speed, fuel-saving air- and coolant-flow products by hydraulically isolating engine-input speeds and minimizing power consumption under high-speed operation and light-engine loads where maximum flow rates are not required.
The Visco pump’s control logic is embedded in an engine-control module. Although the pump is tied to a belt drive, energy is transferred hydraulically to an impeller. The amount of energy transfer depends on the amount of silicone oil in an operating chamber managed through a closed-loop control system.
The Visco coolant pump is designed for the life of the vehicle and does not require periodic maintenance, Behr says. Estimated fuel-economy savings of one percent for long-haul truck applications is based on average engine power of 100 kW.
