Coordinated thermal management capabilities are crucial for automotive energy efficiency, ensuring that the engine or battery operates at its optimal temperature for maximum efficiency and minimum energy consumption and emissions. Thermal management systems include electronic water pumps, electronic thermostats, and cooling fans.
Active grille
The primary function of the air intake grille is to draw in air and assist engine combustion; hence, gasoline-powered vehicles typically feature large grilles of various shapes. Some cars on the market now are equipped with active air intake grilles, which control the amount of air intake by adjusting their opening and closing angle. What is the purpose of this?
First, when starting a cold engine, the engine needs to reach its optimal operating temperature as quickly as possible. Opening the grille to let cold air blow out continuously is not conducive to the engine warming up. Therefore, closing the grille at this time can speed up the engine's warm-up efficiency, and the car's air conditioning can also provide warm air sooner.
Secondly, when the engine is cruising at high speed, the engine speed is low and stable, and the heat is not high, so it does not need as much air cooling. At this time, closing the air intake grille forces the oncoming airflow to flow along the front of the car and the chassis, reducing wind resistance and improving fuel economy.
Finally, when the engine temperature is too high, the air intake grille will automatically open to cool down quickly. So when will the engine temperature rise? For example, when the vehicle has been driving on dirt roads and muddy sections for a long time, the radiator becomes dirty and its heat dissipation capacity is insufficient, resulting in excessively high coolant temperature; the thermostat may not be working properly, resulting in a large temperature difference between the inlet and outlet water pipes; in hot summer weather, the car may be driven at high temperatures for a long time, causing the radiator to " boil over, " and so on.
The active air intake grille shutter mechanism utilizes Xiros self-lubricating plastic ball bearings, perfectly meeting multiple customer requirements: the lowest possible coefficient of friction, resistance to dirt, high and low temperature resistance, and minimal weight. Meanwhile, for longitudinal louvers, we also offer the iglidur J sliding bearing as a low-friction, low-cost solution.
electric water pump
Coolant not only cools the vehicle but also prevents corrosion and frost formation. Coolant pumps, controllers, and valves distribute coolant throughout the vehicle and control its operation as needed. Traditional mechanical water pumps operate in tandem with the engine, handling heavy loads and high speeds, making precise temperature control difficult and leading to significant energy consumption. Electronic water pumps, on the other hand, automatically control engine temperature. With the increasing electrification and intelligence of automobiles, electronic water pumps will gradually replace traditional mechanical water pumps.
What characteristics are required for the bearings in an electric water pump?
1. Clearance between shaft and bearing: The lower the water absorption rate of the bearing material, the better. In addition, the clearance between shaft and bearing needs to be calculated to prevent jamming.
2. Temperature resistance: When the speed exceeds 1~2m/s , the temperature will reach 150℃ . Iglidur® H370 can withstand temperatures up to 200℃ and is one of the most commonly used materials.
3. Start-up tolerance: During startup, there is no coolant, and the bearings are in a dry-running state. Iglidur can meet this brief high-temperature, high-speed operating condition.
4. Chemical resistance: The adhesive adheres to the fiber surface, ensuring a strong bond between the base material and the fiber, and plays a decisive role in the material's mechanical strength and chemical resistance. This is why iglidur® H370 is used in water pumps.
5. Economic Efficiency: Ceramic or graphite bearings are commonly used, but their cost is relatively high. In similar operating conditions, price is not the decisive factor for customers choosing Iglidur bearings. However, if Iglidur can meet performance requirements while reducing costs, no one would refuse to try the change.
6. Injection molding allows for greater design freedom: Whether it's graphite, ceramic, or iglidur 370 bearings, when standard structures cannot meet increasingly demanding operating conditions, it's necessary to consider enhancing the hydrodynamic characteristics of the bearing structure. For example, we can create grooves on the inner wall or flange of the bearing. Because of the injection molding process, the structural design of iglidur H370 bearings is more flexible and free.
thermostat
The thermostat in a car controls the flow of coolant into the engine. The engine temperature must be neither too high nor too low. The thermostat automatically adjusts the amount of coolant entering the radiator based on the coolant temperature, maintaining the coolant at its optimal operating temperature. This plays a crucial role in the engine's lifespan and efficiency.
When the vehicle is first started, the coolant temperature is relatively low. The thermostat automatically closes the passage to the radiator and opens the passage to the water pump, allowing the coolant to circulate in a small loop. This helps the engine warm up quickly and reach its optimal operating temperature as soon as possible. As the coolant temperature rises, the thermostat adjusts its opening, allowing some coolant to enter the radiator, slowing down the temperature rise. At this point, both the large and small loops exist simultaneously. When the coolant temperature exceeds the optimal operating temperature, the thermostat opens fully. The coolant then flows through the radiator and thermostat valve, and back to the engine via the water pump, completing a large loop to maintain the coolant temperature in the engine at its optimal level.
If the thermostat malfunctions, the valve will remain either closed or open, causing the engine to operate at either excessively high or low temperatures. Overheating reduces charging efficiency, decreases engine power, increases the tendency for pre-ignition and knocking, prematurely damages components, and worsens lubrication between moving parts, accelerating wear. Conversely, excessively low temperatures make ignition difficult or slow, resulting in reduced engine power; increased oil viscosity also increases resistance between moving parts. Both excessively high and low temperatures severely shorten the engine's lifespan.
Traditional thermostats open valves by causing paraffin wax to expand from a solid to a liquid state upon heating. Currently, there's a product commonly called an electronic thermostat, which adds an electric heating element to a mechanical paraffin thermostat. When the engine is cold and under heavy load, the electronic components intervene, heating the paraffin wax and causing the thermostat valve to open earlier. However, this " electronic thermostat ," in its valve operation principle, is still a mechanical paraffin thermostat. The electronic thermostat discussed in this article, on the other hand, transmits the resistance change signal of a thermistor to the engine's ECU , where an electronic actuator opens the valve. Compared to paraffin thermostats, this new type of electronic thermostat uses high-temperature resistant plastic materials for both the housing and the valve's operating mechanism. This not only reduces weight but also avoids rust and corrosion problems. The preset optimal temperature is not limited by the melting point of paraffin wax, making the cooling system more agile and intelligent.
For the valve shaft position of the latest generation of mass-produced electronic thermostats, we selected bearings made of iglidur H1 material. Why choose iglidur H1 ?
1. High Temperature Resistance: iglidur H1 material can withstand temperatures up to 200℃ , and can even withstand short-term high temperatures of 240℃ . The boiling point of high-quality coolant is usually above 110℃ . Even if the engine coolant temperature reaches the boiling point, iglidur H1 bearings can still withstand loads of over 45MPa , ensuring reliable operation under complex fluid pressure environments.
2. Extremely low water absorption: Under standard atmospheric pressure, 23°C and 50% relative humidity, the water absorption rate of iglidur H1 sliding bearing is 0.1% , and the saturated water absorption rate when fully immersed in water is only 0.3% , which is one of the materials with the lowest water absorption rate in the iglidur series.
3. Extremely low coefficient of friction at high temperatures: The advantage of iglidur H1 sliding bearing material is that even when the bearing is exposed to high temperatures and corrosive chemicals, it still has extremely high wear resistance and an excellent coefficient of friction. In an aquatic environment, the coefficient of friction against a rigid shaft can reach 0.04 .
4. High chemical resistance: All H- series materials have strong chemical resistance and can maintain performance and dimensional stability in pure alcohol, glycerol, and ethylene glycol coolants.
5. High cost performance: Compared with ceramic or graphite bearings, iglidur® sliding bearings have a strong cost advantage.
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