Can a rear engine bus use a fan drive?
For a rear engine bus, front cooling air is not available and the cooling flow must be generated completely by the fan drive. In addition, vehicle designers are challenged to meet styling and Tip Clearance Direct Fan Drive Hydraulic Fan Drive Engine Tip Clearance Reduced by 75% Engine
What are the control factors for a fan clutch?
Some clutches are electronically controlled (instead of bi-metallic strip). These provide the potential to control the level of engagement depending on any number of inputs. Common controlling factors might include engine oil temperature, transmission oil temperature, coolant temperature, AC system pressures and ambient air temperature.
Is there a way to control the speed of a fan?
high-frequency fan control. A 2-wire fan has power and ground terminals. A 3-wire fan has power, ground, and a tachometric (“tach”) output, which provides a signal with frequency proportional to speed. A 4-wire fan has power, ground, a tach output, and a PWM-drive input.
Is the fan drive the same as the fan clutch?
The two terms “fan clutch” and “fan drive” are interchangeable. Although the fan clutch is driven by the engine, it is designed to stay “idle” in off mode and to turn on (with the engine as the primary force) as the engine temperature increases.
For a rear engine bus, front cooling air is not available and the cooling flow must be generated completely by the fan drive. In addition, vehicle designers are challenged to meet styling and Tip Clearance Direct Fan Drive Hydraulic Fan Drive Engine Tip Clearance Reduced by 75% Engine
How does a hydraulic fan drive system work?
Hydraulic fan drive systems enable full fan control yielding significant power and fuel savings. Parker hydraulic fan drive systems are efficient throughout the engine and vehicle’s operating range. Traditional on/off clutch solutions operate only at maximum speed and can suddenly drain power to the vehicle and even require downshifting.
How is the speed of the fan motor adjusted?
In the fan drive circuit, fan speed is adjusted by providing a varying Pulse Width Modulated electrical current signal to the proportional relief valve which controls the flow to the fan motor. Excess flow is bypassed to the reservoir. Performance and Value:
Which is fan drive technology does Parker use?
Parker is in the unique position of having three fan drive motor and pump technologies which can be supplied for the fan drive function on a bus. Each of these technologies, Gear, Vane and Piston, offer distinct advantages in terms of initial purchase cost, life time cost, efficiency and noise.
