Ventilator bearing

(1) Function

In order to make the engine maintain the best working temperature and reduce power consumption as much as possible, modern engines generally use adjustable ventilator. When the running airflow and radiation heat dissipation are enough to ensure that the optimal working temperature is not exceeded, the ventilator is in a stop state. When the optimal working temperature is exceeded, the ventilator enters the working state.

This discontinuous working ventilator has a variety of transmission structures, and different structures of the ventilator has different requirements for bearings.However, when directly installed in the ventilator impeller, the biggest problem facing the bearing is to bear a large load and may be 150-230 degrees Celsius high temperature.

Therefore, in the automobile ventilator, the bearing must first pay attention to the lubrication and sealing problems, and then ensure that the bearing outer ring and light metal shell still have the appropriate match even in the higher working temperature.In addition, the bearing should be able to bear the higher torque load caused by the imbalance of the ventilator and carry out accurate guidance, and the friction torque should be reduced as far as possible to benefit energy saving and noise reduction.

(2) Design analysis

The common ventilator uses the silicone oil clutch or the electromagnetic clutch to control the cooling fan. Taking the ventilator using the silicone oil clutch as an example, the bearing of the ventilator is analyzed.In the ventilator with silicone oil clutch, the pump wheel of the clutch is driven by the engine, the turbine is fixedly connected with the fan, and the bearing is installed between the pump wheel shaft and the turbine shell.The pump wheel transmits the torque to the turbine through the silicone oil, and the inlet and outlet of the silicone oil in the pump wheel and turbine working chamber are controlled by the bimetallic temperature sensing element directly installed behind the radiator. The fan speed is automatically adjusted according to the engine temperature, so as to control the engine temperature.

1. Deep groove ball bearings

Deep groove ball bearing is the most common type of rolling bearing.The deep groove ball bearing of this type consists of an outer ring, an inner ring, a group of steel balls and a group of cages.There are two types of deep groove ball bearings: single row and double row. Deep groove ball structure is also divided into sealed and open structure. Open type means that the bearing does not have a sealed structure.The dustproof seal cover is made of steel sheet stamping, which only plays a simple role in preventing dust from entering the bearing raceway.Oil-proof type is contact oil seal, which can effectively prevent grease spillover in the bearing.

Single row deep groove ball bearing type code is 6, double row deep groove ball bearing code is 4.Its structure is simple, easy to use, is the production of the most common, the most widely used kind of bearings.

2. Double bearing

Heavy ventilators require wider support seats and corresponding double row angular contact ball bearings or deep groove ball bearings mounted in pairs.The invention relates to a supporting structure of a car ventilator with two sets of deep groove ball bearings

3. Needle roller bearings

If sufficient space is available, two sets of deep groove ball bearings can also be used to support the entire ventilator assembly, while a set of stamped outer ring needle roller bearings can be used to support the turbine and fan on the pump wheel shaft.The ventilator assembly is positioned and supported by two sets of grease-lubricated sealed deep groove ball bearings. Only one set of stamped outer ring needle roller bearing directly installed in the ventilator is under high temperature, so the lubrication, sealing and matching of the needle roller bearing must be designed accordingly.