DID YOU KNOW HOW A VISCOUS CLUTCH WITH BIMETALLIC ACTIVATION WORKS?

May 18, 2021

The activation of this clutch is performed by a bimetal, in other words, by two assembled alloys with different expansion coefficients.

Depending on the airflow temperature, which comes from the radiator and falls upon the bimetal, the behaviour of the clutch may vary.

When the airflow temperature increases (the coolant temperature is high), the bimetal is prone to bend towards the side with less dilatation coefficient, and the clutch valve opens. As a result, the viscous fluid enters into the clutch working chamber. In this way, the clutch engages, and the power is transmitted to the fan.

When the coolant temperature is lower, the airflow temperature that falls upon the bimetal decreases and the last one comes back to a resting state, closing the valve. The clutch disengages because of this, and it stops transmitting power to the fan.

Discover here our viscous clutches with bimetallic activation!