The Dayco friction wheel is a component developed to transmit power from the crankshaft pulley to the water pump pulley.
The main advantage of the friction wheel is the ability to switch on the water pump, via an electromechanical actuator. The actuator, driven by an electronic control unit (through an electrical signal) can activate the water pump by transmitting mechanical power to the belt. When the engine is cold the coolant will not circulate until the engine has reached normal operating temperature because the water pump is switched off: this will warm up the engine more quickly, reduce fuel consumption and keep exhaust pollution within the EURO 5 emission limits.
Additionally, there are fewer mechanical losses during the disconnection phase of the water pump. Faster heating of the passenger compartment can be achieved thus increasing passenger comfort in cold weather. Dayco is the OE supplier of the entire friction wheel system, which includes a water pump pulley, tensioner, Poly-V belt and friction wheel.