Interpretation of silicone oil clutch


Many people are interested in the whirring of Toyota SUVs. It's very simple to investigate the reasons. However, the ingenious use of a fan coupler is not the patent of Toyota. It was developed and produced by bog Warner in the 1950s. As we all know, six of the world's top ten engines in 2007 are made of bogewana's systems and components, including the Chrysler hemi 5.7 engine we are familiar with, and the Audi 2.0T engine we are familiar with. Later, the Volkswagen seven speed double clutch gearbox DSG is even more a masterpiece of borgwana.


Continue to talk about the silicone oil clutch, the temperature sensing elements are bimetal coil spring temperature sensors. Its working process:


(1) when the temperature of the air flowing through the radiator increases, the bimetal temperature sensor is heated and deformed, forcing the valve plate shaft to rotate, and opening the oil inlet hole on the driven plate. The silicon oil stored between the driven plate and the front cover flows into the working chamber between the driving plate and the driven plate, the clutch is engaged, and the fan speed increases. The higher the air temperature is, the larger the oil inlet opening is, and the faster the fan speed is.


(2) when the temperature of the air flowing through the radiator drops, the bimetal temperature sensor returns to its original state, the valve plate closes the oil inlet hole, under the effect of centrifugal force, the silicon oil returns from the working cavity to the oil storage cavity through the oil return hole, the clutch is separated, the fan speed becomes very low, even idling, to ensure that the engine quickly reaches the normal working temperature, and the cab heating system works normally. (take strip driving plate and driven plate for example. If they are round, they are driving plate and driven plate).


When driving in the desert, the silicone oil clutch is also an important part of many parts. The vehicle starts to rush to the slope at high speed. Once the air temperature around the fan reaches the critical value, it immediately starts to fight and try its best to drive away the extra heat. Especially for the automatic transmission, the fan is also required to take away the temperature of the gearbox. When the vehicle starts to go downhill or walk to the gentle area, the engine compartment temperature drops and the silicone oil returns to the oil storage tank. The fan is in a half working state, the speed decreases and the sound decreases. Noise is also a kind of pollution. And the power of the fan comes from the crankshaft, and it also needs to disperse part of the power, so that the half working state can reduce the fuel consumption and noise. It's really a good helper for energy conservation and emission reduction.


So the problem of car owners is coming. When the clutch is closed when it is hot, the sound of fan running at full load can be understood. Why is the sound so loud when the car is cold? Generally, the water temperature is at the normal working temperature during each flameout, and there is a certain amount of silicone oil in the working chamber. After flameout, the engine crankshaft is no longer running, and the fan has no power source. Although the temperature will gradually drop after stopping, there is no centrifugal force, and the silicone oil in the working chamber cannot return to the oil storage chamber, which is equivalent to that the silicone oil clutch is not separated. Therefore, the next time the engine is started, a certain amount of silicone oil remains in the working chamber, the cold car is at high idle, and the fan speed must be high. So there is such a beautiful roar! But soon, under the effect of centrifugal force, the silicon oil slowly returns to the oil storage chamber, the fan speed decreases, and the sound decreases.


Author: Zhang Bo