How does viscous fan coupling work

This in turn will lead to the engine overheating as the cooling process is disrupted. Leaking silicone fluid, disengaging the fan coupling. The bimetal sensor governs the functioning of the viscous fan coupling. Primarily, there are two kinds of bimetal sensor systems: plate and coil.

Both of them work under the same principle, as explained previously. The only difference is that whilst the coil expands and contracts to turn the rotation plate, the bimetal contracts and bends. This moves the slide plate and allows the silicone fluid to move from the reservoir chamber to the cavity. BGA viscous fan couplings are fully tested before release to the aftermarket to ensure high quality of the replacement products.

The process involves testing the engagement and disengagement temperatures of the product; whilst comparing the data against an OE part to warrant correct performance. Being a high-value ticket item at OE level, dealers service only a very limited business while the aftermarket for this product is shared between suppliers. Although these suppliers have gained a small foothold within the market, none of them offers a full range.

Factors, therefore, need to multi-source parts to support the varied UK car parc, which is neither practical nor cost effective. Aftermarket specialist BGA have the most comprehensive range of viscous fan couplings, consisting of 60 references.

BGA has further planned NTR introductions to expand the range to around 80 references throughout , to keep the range relevant to the UK market. Viscous fan couplings have been a logical addition to the BGA cooling portfolio.

Factors too should treat it as an associated sale for the relevant applications. When replacing the water pump, it is best practice to check that the viscous fan coupling is operating correctly as well. In the current market this part could be overlooked during the replacement of the water pump. This could lead to factors missing out on a sales opportunity, whilst the vehicle owner potentially would have to pay a second labour charge to replace the coupling at a later stage.

Supported by excellent stocking and logistics from ourselves, the comprehensive viscous fan couplings range from BGA is clearly a reliable choice for the motor factor. Viscous fan couplings are a popular yet under-capitalised segment in the aftermarket. Viscous drives control how fast an engine fan spins with remarkable accuracy. Oil is released from a reservoir into grooves that allow for increased or decreased friction depending how much cooling is needed.

The fluid is then pumped out of the working area and into reservoir. Viscous fan drives have been a staple in European on- and off-highway applications for the better part of a decade. Most off-highway equipment in the United States deploys them, as well.

And long-haul trucks are starting to convert to this new technology in waves. Viscous fan drives deliver only the amount of cooling needed — nothing more, nothing less. Fully-variable clutches are the most technologically advanced, efficient option available when it comes to engine cooling systems. While this is useful in some applications, viscous drives offer a greater degree of precision.

When an engine can devote less energy to cooling and more to turning wheels, that means fuel savings. Once that happens, the fan slows way down, consuming less fuel. The fan drive's valve, clutch, and fluid reservoir all spin together, which puts less drag on the engine. Even better, the cooling fan in a viscous drive can vary its speed to meet precise engine cooling requirements and cooling system temperature.

A fixed fan can only run at one speed. The fan speed signal and clutch allow for precise engine coolant and charged air adjustments, improving efficiency. The valve arm opens to push silicone oil in to the working chamber. As the silicone oil flows between the input and output clutch plates, it creates shear forces. This gradual buildup forces the two plates to spin at similar speeds, thus allowing a smooth change in the fan speed. Since the fan slows when when high power is not needed, your vehicle gains horsepower and torque for better engine performance and mileage.

When cooling is needed, the engine control unit ECU triggers the clutch, which puts the fan into faster rotation again. Integral to all of this? The flux ring , which fits inside the fan drive and supports fan drive performance. You might have noted the extraordinary aspect ratio between the length and the width of the component.

The height makes this flux ring complex and difficult for other powder metal manufacturers to produce. With powdered metal parts, if you need a part width of 0. But this flux piece is , which is double a normal ratio for a part this thick. All this is done while maintaining the magnetic performance of the part. As you can see in the video, the flux ring and fan drive as a whole plays a big role in improving vehicle performance.

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